Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TOXICOLOGY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 541 records · Page 30Linked to original sources
PubMed1992

Toxicology and Carcinogenesis Studies of C.I. Pigment Red 23 (CAS No. 6471-49-4) in F344 Rats and B6C3F1 Mice (Feed Studies).

C.I. Pigment Red 23 is a bluish red commercial dye used as a coloring agent in paints, inks, rubber, plastics, lacquers, and paper. Toxicology and carcinogenicity studies were conducted by feeding groups of rats and mice diets containing C.I. Pigment Red 23 (greater than 96% pure) for 17 days, 13 weeks, and 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and in Chinese hamster ovary cells. 17-Day Studies: Groups of five rats and five mice of each sex were fed diets containing 0, 6,000, 12,500, 25,000, 50,000, or 100,000 ppm C.I. Pigment Red 23 for 15 to 17 days. All rats and all female mice lived until the end of the studies. Two male mice in the 12,500 ppm dose group died accidentally. No other deaths occurred among male mice. Final mean body weights of rats and mice receiving C.I. Pigment Red 23 were within 10% of those of the controls. Feed consumption by exposed animals was similar to that of the controls. Hematocrit value, hemoglobin concentration, and erythrocyte count were decreased in the 50,000 and 100,000 ppm groups of rats. A corresponding decrease was not seen in mice. Absolute and relative organ weights of exposed animals were generally similar to those of the controls. No chemical-related gross lesions were seen in rats or mice. 13-Week Studies: Groups of 10 rats and 10 mice of each sex were fed diets containing 0, 3,000, 6,000, 12,500, 25,000, or 50,000 ppm C.I. Pigment Red 23 for 13 weeks. All rats and mice lived until the end of the studies. Final mean body weights of rats and mice receiving C.I. Pigment Red 23 were within 10% of those of the controls. Feed consumption by exposed animals was similar to that of the controls. In 50,000 ppm male rats, hematocrit and hemoglobin concentrations and erythrocyte counts were significantly less than those of the controls. In female rats receiving 3,000, 6,000 and 50,000 ppm C.I. Pigment Red 23, lymphocyte counts were significantly higher than the control values. Leukocyte counts in 3,000 ppm females were also significantly increased. Female mice in the 6,000 ppm dose group had significantly lower hematocrit and hemoglobin concentrations than did untreated females. Hematology parameters in exposed males were similar to those of untreated males. There were no biologically significant differences in organ weights among dosed and control rats. Absolute and relative liver weights of male mice receiving 12,500 ppm C.I. Pigment Red 23 were significantly increased compared to those of the controls. Absolute and relative thymus weights for all but 12,500 ppm female mice were significantly lower than those of the controls. No chemical-related gross or histopathologic lesions occurred in rats or mice. 2-Year Studies: Survival, Body Weights, Feed Consumption, and Clinical Findings Because levels of C.I. Pigment Red 23 as high as 50,000 or 100,000 ppm in the feed did not adversely affect survival and mean body weights in the 17-day and 13-week studies, nor cause any chemical- related lesions, doses of 0, 10,000, 25,000, or 50,000 ppm were selected for the 2-year studies. Doses higher than 50,000 ppm (5%) are not used in 2-year studies because they may lead to excessive dilution of nutrients in feed which in turn could produce nutritional deficiencies. Survival rates of mid- and high-dose male and of high-dose female rats were significantly greater than those of the controls, due primarily to a chemical related decreased incidence of mononuclear cell leukemia in these groups (survival in male rats: control, 22/50, low-dose, 29/50, mid-dose, 36/50, high-dose, 35/51; female rats: 29/50, 34/50, 33/50, 40/50). Survival of mice was not affected by the administration of C.I. Pigment Red 23, although survival of low-dose male mice was significantly lower than that of controls (male mice: 29/51, 17/53, 27/52, 30/51; female mice: 35/50, 34/49, 36/50, 35/49). The decreased survival in the low- dose males was associated with evidence of body trauma and secondary septicemia caused by fighting. From approximately week 20 of the study, the group mean body weight, the group mean body weights of exposed female rats were consistently lower than those of controls; at week 101, mean body weights of mid- dose (25,000 ppm) and high-dose (50,000 ppm) females were 6% and 8% less, respectively. The final mean body weights of exposed male rats and male and female mice were similar to those of controls. Feed consumption values for exposed male and female rats and mice were similar to those of the controls and there were no clinical signs associated with the administration of C.I. Pigment Red 23. Pathology Findings: Renal tubule adenomas occurred in two high- dose male rats. Renal tubule carcinomas occurred in one high-dose male and one mid-dose male rat. No renal tubule neoplasms were seen in the controls. Renal tubule neoplasms are uncommon and have occurred in 8/499 (1.6%) untreated historical controls with a range of 0% to 6%. The residual halves of kidneys from control and high-dose males were step sectioned and examined; renal tubule adenomas were observed in a control male and in two additional high- dose males. Because of the low numbers of renal neoplasms, it is uncertain if they were related to chemical administration. The incidence of renal tubule hyperplasia (3/50, 6/48, 5/50, 8/50) and the mean severity of nephropathy were also slightly increased in high-dose male rats. The incidence of mononuclear cell leukemia occurred with a significant negative trend in exposed male and female rats. No chemical-related increases in the incidence of neoplasms were observed in mice of either sex. There was a chemical-related increase in the incidence of hyperplasia (male mice: 0/49, 1/48, 1/50, 7/48; female mice: 6/49, 14/49, 43/50, 47/49) and hyperkeratosis of the forestomach epithelium attributed to chemical administration. Genetic Toxicology: C.I. Pigment Red 23 was mutagenic in Salmonella typhimurium strains TA100, TA1537, and TA98 with and without exogenous metabolic activation (S9), but it was not mutagenic in strain TA1535. C.I. Pigment Red 23 induced sister chromatid exchanges in Chinese hamster ovary cells in the absence of S9, but not with S9 activation. The pigment was negative for the induction of chromosomal aberrations in Chinese hamster ovary cells both in the presence and absence of S9. Conclusions: Under the conditions of these 2-year feed studies, there was equivocal evidence of carcinogenic activity of C.I. Pigment Red 23 in male F344 rats as evidenced by a marginally increased incidence of renal tubule cell neoplasms. There was no evidence of carcinogenic activity of C.I. Pigment Red 23 in female F344 rats fed diets containing 10,000, 25,000, or 50,000 ppm. Mononuclear cell leukemia occurred with a decreased incidence in male and female rats receiving C.I. Pigment Red 23. There was no evidence of carcinogenic activity of C.I. Pigment Red 23 in male and female B6C3F1 mice fed diets containing 10,000, 25,000 or 50,000 ppm. The severity of kidney nephropathy was increased in exposed male rats. In mice, C.I. Pigment Red 23 caused an increase in hyperkeratosis and epithelial hyperplasia of the fore- stomach. Synonyms: 2-Naphthalenecarboxamide; 3-hydroxy-4-((2-methoxy-5- nitrophenyl)azo)-N-(3- nitrophenyl); 3-hydroxy-4-((2-methoxy-5- nitrophenyl)azo)-3 -2-naphthanilide; Alkali Resistant Red Dark; Calcotone Red 3B; Carnation Red Toner B; CI 12355; Congo Red R- 138; Fenalac Red FKB Extra; Malta Red X2284; Naphthol Red B; Naphthol Red T Toner 35- 6001; Naphthol Red Deep 10459; Pigment Red BH; Rubescence Red MT-21; Sanyo Fast Red 10B; Sapona Red Lake RL-6280; Sengale Light Rubin RG; Textile Red WD-263

Journal Article↗
PubMed1993

Toxicology and Carcinogenesis Studies of Mercuric Chloride (CAS No. 7487-94-7) in F344 Rats and B6C3F1 Mice (Gavage Studies).

Mercuric chloride is an inorganic compound that has been used in agriculture as a fungicide, in medicine as a topical antiseptic and disinfectant, and in chemistry as an intermediate in the production of other mercury compounds. The widespread use of mercury has resulted in increased levels of mercury in rivers and lakes. Mercuric chloride was evaluated in toxicity and carcinogenicity studies because of its extensive use and its occurrence as an environmental pollutant, and because of the lack of adequate long-term rodent studies. Toxicology and carcinogenesis studies were conducted by administering mercuric chloride (greater than 99% pure) in deionized water by gavage to groups of F344 rats or B6C3F1 mice for 16 days, 6 months, and 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium (strains TA98, TA100, TA1535, and TA1537), in mouse lymphoma L5178Y cells, in Chinese hamster ovary cells, and in Drosophila melanogaster. 16-DAY STUDIES: Groups of five rats of each sex received 0, 1.25, 2.5, 5, 10, or 20 mg mercuric chloride/kg body weight and groups of five mice of each sex received 0, 5, 10, 20, 40, or 80 mg/kg in deionized water by gavage for 12 dose days. Two male rats in the 20 mg/kg group died in the first week, as did all male and four female mice from the 80 mg/kg group and one male mouse from the 40 mg/kg group. The final mean body weight of male rats receiving 20 mg/kg was 10% lower than that of the controls; the final mean body weight of 20 mg/kg females was 9% lower than that of the controls. Final mean body weights and body weight gains of dosed mice were similar to those of the controls. Absolute and relative kidney weights of male rats receiving 2.5 mg/kg or greater doses and of female rats administered 5 mg/kg or more were significantly greater than those of the controls. Absolute kidney weights of mice were significantly increased in all male dose groups and in the 40 mg/kg female dose group; relative kidney weights of dosed male and female mice were significantly greater than the controls. Analysis of kidney, liver, and brain tissues for mercury residues revealed that the highest mercury concentration was in the kidneys of rats and mice. Acute renal tubule nephropathy occurred in dosed rats and was slightly more severe in males than in females. Chemical-related lesions in mice included renal tubule necrosis, inflammation and necrosis of the forestomach, and necrosis of the glandular stomach. 6-MONTH STUDIES: Groups of 10 rats of each sex received 0, 0.312, 0.625, 1.25, 2.5, or 5 mg mercuric chloride/kg body weight in deionized water by gavage for 26 weeks. Groups of 10 mice of each sex received 0, 1.25, 2.5, 5, 10, or 20 mg/kg in deionized water by gavage for 26 weeks (males) or 27 weeks (females). No deaths related to mercuric chloride administration occurred in rats or mice. Mean body weight gains of male rats that received 5 mg/kg and all female rat dose groups that received 0.625 mg/kg or greater were significantly lower than the controls. The final mean body weight and body weight gain of male mice in the 20 mg/kg group were significantly lower than those of the controls; final mean body weights and body weight gains of other dosed male mice and all dosed female mice were similar to those of the controls. Absolute and relative kidney weights of all dosed male rats and of female rats that received 0.625 mg/kg or greater were significantly greater than those of the controls. In male mice, absolute kidney weights in the three highest dose groups were significantly increased; no biologically significant differences in organ weights occurred in female mice. Analysis of kidney, liver, and brain tissues for mercury residues revealed the highest mercury concentration in the kidneys of rats and mice. The severity of chronic nephropathy increased with dose in male rats. Cytoplasmic vacuolation of renal tubule epithelial cells was observed in male mice in the 5, 10, and 20 mg/kg groups. No histopathologic changes in female mice were related to chemical exposure. 2-YEAR STUDIES: Groups YEAR STUDIES: Groups of 60 rats of each sex received 0, 2.5, or 5 mg mercuric chloride/kg body weight and groups of 60 mice of each sex received 0, 5, or 10 mg/kg in deionized water by gavage 5 days per week for 2 years. The doses were based on decreased weight gains in rats receiving 10 and 20 mg/kg and the decreased weight in male mice receiving 40 mg/kg during the 16-day studies, and on the decreased weight gains and toxicity results seen in the 6-month studies. Increased absolute and relative kidney weights in rats and male mice in the 6-month studies and degenerative renal changes suggested that higher dose levels would result in inadequate survival rates for a 2-year study. 15-Month Interim Evaluations: Relative kidney weights were significantly increased in dosed rats and female mice. The severity of nephropathy was increased in male rats, but not in females. High-dose male and female rats had minimal to mild hyperplasia of the basal cell layer in the forestomach epithelium (diagnosed as acanthosis); this lesion was not found in control or low-dose rats. Male mice had an increased severity of vacuolation of the renal tubule epithelium; no chemical-related lesions occurred in the kidneys of females. The incidence of inflammation of the olfactory epithelium lining the nasal cavity increased in male and female high-dose mice. Survival, Body Weights, and Clinical Signs: Survival of dosed male rats was lower than that of the controls (26/50, 10/50, 5/50); survival of dosed female rats was similar to that of the controls (35/50, 28/49, 30/50). Although more than 60% of the mice in each dose group survived to study end, survival rates of high-dose male mice and dosed female mice were lower than those of the controls (males: 36/50, 36/50, 31/50; females: 41/50, 35/50, 31/50). The final mean body weights of high-dose male and female rats were 15% and 14% lower than controls, respectively. The mean body weight of low-dose female rats was generally similar to controls throughout the 2-year study; the mean body weight of low-dose male rats was similar to that of the control through week 89. In mice, mean body weights of all male and female dose groups were similar to those of the controls throughout the studies. Pathology Findings: Chronic nephropathy appeared to develop at an accelerated rate and led to decreased survival in both dosed male rat groups. Secondary effects of renal dysfunction in dosed male rats resulted in increased incidences of fibrous osteodystrophy of the bone, mineralization of various tissues, and parathyroid gland hyperplasia. Based on evaluations of single and step sections, the incidence of renal tubule hyperplasia was increased in high-dose male rats (control, 3/50; high-dose, 10/50), but the incidences of renal tubule adenoma in high-dose and control males were similar (4/50, 5/50). Renal tubule hyperplasia was also slightly increased in high-dose female rats (2/50, 5/50) and adenomas were seen in high-dose females, but not in controls (0/50, 2/50). Incidences of forestomach hyperplasia in rats were markedly increased in dosed males (3/49, 16/50, 35/50) and high-dose females (5/50, 5/49, 20/50). Squamous cell papillomas of the forestomach were found in 3 low-dose and 12 high-dose males and in 2 high-dose females. No squamous cell carcinomas were found. The incidence of thyroid follicular cell carcinoma was marginally increased in high-dose male rats (1/50, 2/50, 6/50). However, a corresponding increased incidence in follicular cell adenomas (1/50, 4/50, 0/50) or hyperplasia (2/50, 4/50, 2/50) in males did not occur, and the overall incidence of follicular cell neoplasms was not significantly increased (2/50, 6/50, 6/50). The incidence of nasal mucosa inflammation in male and female rats was increased in the high-dose groups (male: 9/50, 8/47, 18/50; female: 0/49, 5/49, 15/50) and may have been related to chemical administration. The incidences of mammary gland fibroadenomas were significantly decreased in dosed female rats (15/50, 5/48, 2/50). The incidence and severity of nephropathy were increased in dosed mice; secondary effects of renal dysfunction did not occur. Renal tubule hyperplasia was found in one control and two high-dose male mice. Two renal tubule adenomas and one renal tubule adenocarcinoma were seen in high-dose male mice. Additional step sections revealed focal hyperplasia in another control male; no additional renal tubule neoplasms were found in high-dose or control males. Proliferative lesions of the renal tubule epithelium were not found in female mice. The incidence of metaplasia of the olfactory epithelium increased with dose in male and female mice. No other biologically significant lesions were found. GENETIC TOXICOLOGY: Mercuric chloride was not mutagenic in Salmonella typhimurium strains TA100, TA1535, TA1537, or TA98 with or without exogenous metabolic activation (S9). Induction of sex-linked recessive lethal mutations in germ cells of male Drosophila melanogaster did not occur when mercuric chloride was administered in feed or by injection. However, positive results were obtained in mutagenicity tests with mammalian cells. In the absence of S9, mercuric chloride induced trifluorothymidine resistance in mouse L5178Y cells and chromosomal aberrations in Chinese hamster ovary cells. In the Chinese hamster ovary cell test for induction of sister chromatid exchanges, mercuric chloride produced a negative response without S9 and a weakly positive response in the presence of S9. CONCLUSIONS: Under the conditions of these 2-year gavage studies, there was some evidence of carcinogenic activity of mercuric chloride in male F344 rats based on the increased incidence of squamous cell papillomas of the forestomach. Marginally increased incidences of thyroid follicular cell adenomas and carcinomas may have been related to mercuric chloride exposure. There was equivocal evidence of carcinogenic activity of mercuric chloride in female F344 rats based on two squamous cell papillomas of the forestomach. There was equivocal evidence of carcinogenic activity of mercuric chloride in male B6C3F1 mice based on the occurrences of two renal tubule adenomas and one renal tubule adenocarcinoma. There was no evidence of carcinogenic activity of mercuric chloride in female B6C3F1 mice receiving 5 or 10 mg/kg. Nonneoplastic lesions associated with exposure to mercuric chloride included increased severity of nephropathy in male rats and male and female mice. There was an increased incidence of renal tubule hyperplasia in male rats. The incidence of forestomach hyperplasia was increased in dosed male and female rats. Increased incidences of nasal mucosa inflammation were associated with mercuric chloride administration in rats. Increased incidences of olfactory epithelial metaplasia in mice were also associated with mercuric chloride administration. Synonyms: Abavit B, calochlor, corrosive sublimate, dichloromercury, mercuric bichloride, mercury chloride, mercury (II) chloride, mercury bichloride, mercury perchloride, sublimate, sulem, bichloride of mercury, corrosive mercury chloride, perchloride of mercury, mercury dichloride Trade name: Fungchex

Journal Article↗
PubMed1992

Toxicology and Carcinogenesis Studies of C.I. Pigment Red 3 (CAS No. 2425-85-6) in F344/N Rats and B6C3F1 Mice (Feed Studies).

C.I. Pigment Red 3, a yellowish red solid, is widely used for coloring paints, inks, plastics, and rubber, and in textile printing. It is used in a wide range of consumer items such as wallpaper, typewriter ribbons, carbon paper, and art materials. Toxicology and carcinogenicity studies were conducted by feeding groups of F344/N rats and B6C3F1 mice of each sex diets containing C.I. Pigment Red 3 (97% pure) for 2 weeks, 13 weeks, and 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and cultured Chinese hamster ovary cells. 2-Week Studies: Groups of five rats and five mice of each sex were given feed containing 0, 6,000, 12,500, 25,000, 50,000, or 100,000 ppm C.I. Pigment Red 3 for 2 weeks. No chemical-related deaths occurred in rats or mice. Final mean body weights of exposed rats and male mice were lower than controls; female mice that received 6,000 and 50,000 ppm had significantly increased final mean body weights compared to that of the controls. The feed consumption of treated rats and mice was slightly greater than that of the controls, suggesting that C.I. Pigment Red 3 had no adverse effects on the feed palatability. Dose-related decreases in erythrocyte counts and hematocrit values and an increase in reticulocyte counts were observed in rats. Changes in these parameters were observed in mice, but there were no clear, dose-related trends. 13-Week Studies: Groups of ten rats and ten mice of each sex were given feed containing 0, 3,000, 6,000, 12,500, 25,000, or 50,000 ppm C.I. Pigment Red 3 for 13 weeks. No chemical-related deaths were observed in rats or mice. The final mean body weights of exposed female rats were significantly lower than that of the controls; the final mean body weights of exposed male rats and exposed mice were similar to controls. There were significant increases in relative liver and kidney weights of exposed male rats. Increases in the relative liver weights in mice did not occur with a dose-related trend and thus they were not considered related to chemical administration. Sites for the toxicity of C.I. Pigment Red 3 were the bone marrow, kidney, liver, and spleen in rats. Lesions observed in rats included bone marrow hyperplasia, congestion and hematopoietic cell proliferation of the spleen, and iron-positive pigmentation of the spleen, kidney, and liver. Sites for the toxicity of C.I. Pigment Red 3 in mice were the liver, kidney, and spleen in males and the liver and spleen in females. Lesions noted among mice in the spleen were hematopoietic cell proliferation and iron-positive pigmentation. In the liver, there was hematopoietic cell proliferation in male and female mice. Cytomegaly occurred in the renal tubule epithelium of the male mouse kidney. 2-Year Studies: Doses selected for the 2-year feed studies were 0, 6,000, 12,500, and 25,000 ppm for rats and 0, 12,500, 25,000, and 50,000 ppm for mice. The dose selection for rats was based on body weight changes observed for females that received 50,000 ppm; the dose selection for mice was based on the lack of body weight depression or death at the doses tested during the 13-week studies. Concentrations higher than 50,000 ppm in the feed were not used because higher levels might have adversely affected the nutritional value of the diet during the 2-year studies. Body Weight, Feed Consumption, Clinical Findings, and Survival in the 2-Year Studies: Final mean body weights for male rats that received 25,000 ppm, female rats that received 12,500 and 25,000 ppm, and male and female mice that received 50,000 ppm were more than 10% lower than those of the controls. Feed consumption of exposed rats and mice was similar to that of the controls. No clinical findings indicative of toxicity were observed in rats or mice. The survival of low-dose male rats was greater than that of the controls (0 ppm, 28/50; 6,000 ppm, 40/50; 12,500 ppm, 28/50; 25,000 ppm, 20/50). Survival of exposed female rats and exposed male mice was similar to the controls; the survival of high-dose female mice was significantly decreased compared to thcompared to that of the controls (39/50, 37/50, 31/50, 25/50). The reduced survival in this dose group may have been due to the increased incidence of ovarian abscesses. Neoplasms and Nonneoplastic Lesions in the 2-Year Studies: Benign adrenal pheochromocytomas were significantly increased in the 12,500 and 25,000 ppm groups of male rats compared to the controls (22/50, 29/50, 35/50, 34/50). However, malignant neoplasms were not increased in incidence (6/50, 7/50, 10/50, 4/50). The incidence of adrenal pheochromocytomas in dosed groups exceeded the range for NTP historical controls for feed studies (22%-48%), and the increased incidence of this neoplasm was attributed to C.I. Pigment Red 3 administration. Squamous cell papillomas of the skin occurred with a positive trend in male rats (0/50, 4/50, 2/50, 6/50), and the incidence in the high-dose group was significantly greater than that of the controls. A poorly differentiated squamous cell carcinoma (diagnosed as carcinoma) was observed in a control male. The historical control rate for squamous cell papillomas in NTP feed studies is low (16/800 or 2%, range 0%-4%), and the higher incidence of this tumor in male rats may have been caused by the administration of C.I. Pigment Red 3. Hepatocellular adenomas occurred with a positive trend in female rats, with a significantly greater incidence in the high-dose group than in the control group (0/50, 0/50, 1/50, 10/50). This neoplasm has occurred in only one historical control group in NTP feed studies (3/800, range 0%-6%), and the increase in hepatocellular adenomas in female rats was attributed to chemical administration. Chemical-related nonneoplastic lesions observed in the livers of male and female rats included eosinophilic or mixed type foci of cellular alteration. Foci were often accompanied by angiectasis and cystic degeneration in males and by granulomas and cholesterol pigmentation in females. Chronic nephropathy occurred with increased severity in exposed male and female rats. The lesions were more severe in males than in females. Other lesions considered secondary to renal disease included parathyroid gland hyperplasia, fibrous osteodystrophy of the bone, and mineralization of various organs (stomach, intestine, heart, and blood vessels). The increased incidence of hyperplasia of the transitional epithelium of the renal papilla observed in treated rats was considered to be part of the chronic nephropathy. Zymbal's gland carcinoma incidences were marginally increased in the mid- and high-dose male rats (0/50, 0/50, 2/50, 3/50). The incidence in the high-dose group was outside the NTP historical control range (0%-4%), and the Zymbal's gland carcinomas may have been related to C.I. Pigment Red 3 administration. Mononuclear cell leukemias, mammary gland fibroadenomas, and preputial gland/clitoral gland adenomas occurred at lower incidences in exposed male and female rats. The decrease in mononuclear cell leukemia was attributed to the direct effect of C.I. Pigment Red 3 or its metabolites on the mechanism responsible for inducing leukemias in aging rats, while the decreased incidence of mammary gland fibroadenomas might be attributed to decreased body weights in female rats. The cause of the decreased incidences of preputial and clitoral gland tumors is unknown. Tubule adenomas of the renal cortex occurred at a significantly higher incidence in high-dose male mice than in controls (0 ppm, 0/50; 12,500 ppm, 0/50; 25,000 ppm, 0/50; 50,000 ppm, 6/50). Because this tumor occurred only in exposed males and was outside the range for NTP historical controls in feed studies (0%-2%), renal cortical tubule adenomas in male mice were considered to be related to the administration of C.I. Pigment Red 3. Follicular cell adenoma of the thyroid gland occurred with a positive trend in male mice (0/50, 0/49, 1/50, 5/50). Theincidence in the high-dose group was significantly greater than that in the controls. This chemical-related effect is supported by the increased incidence of follicular cell hyperplasia. Because the incidence of this tumor exceeded the range of the historical controls from NTP feed studies (0%-4%), the increase of follicular cell adenoma was attributed to chemical administration. Female mice receiving C.I. Pigment Red 3 had a significant increase in follicular cell hyperplasia but showed no increase in tumor incidence at this site. Focal renal tubule hyperplasia and cystic hyperplasia occurred in exposed male mice but not in the controls. Cytomegaly (karyomegaly) of the renal tubule epithelium was seen in all treated male mice. The severity of the accompanying chronic nephropathy was increased in both male and female mice. Genetic Toxicology: C.I. Pigment Red 3 was mutagenic in Salmonella typhimurium strains TA100 and TA98 in the presence of exogenous metabolic activation (S9); no increases in gene mutation were observed in strains TA1535 and TA1537, with or without S9. C.I. Pigment Red 3 did not induce sister chromatid exchanges or chromosomal aberrations in Chinese hamster ovary cells in either the presence or the absence of S9. Conclusions: Under the conditions of these 2-year feed studies, there was some evidence of carcinogenic activity of C.I. Pigment Red 3 in male F344/N rats as exhibited by increased incidences of benign pheochromocytomas of the adrenal gland. The marginal increase in the incidences of squamous cell papillomas of the skin and Zymbal's gland carcinomas may have been related to C.I. Pigment Red 3 administration. There was some evidence of carcinogenic activity of C.I. Pigment Red 3 in female F344/N rats as indicated by the increased incidence of hepatocellular adenomas. There was some evidence of carcinogenic activity of C.I. Pigment Red 3 in male B6C3F1 mice as exhibited by the increased incidences of tubule adenomas of the renal cortex and follicular cell adenomas of the thyroid gland. There was no evidence of carcinogenic activity of C.I. Pigment Red 3 in female B6C3F1 mice that received 12,500, 25,000, or 50,000 ppm. The incidences of mononuclear cell leukemia and preputial gland tumors in male rats and mononuclear cell leukemia, mammary gland fibroadenoma, and clitoral gland tumors in female rats were lower in the exposed groups. The incidences of liver foci were markedly increased in exposed male and female rats. The severity of chronic nephropathy was increased in male rats and to a lesser extent in female rats given C.I. Pigment Red 3. An increase in the severity of nephropathy was observed in male and female mice; cytomegaly (karyomegaly) of renal tubule epithelium was observed in male mice. Thyroid follicular cell hyperplasia occurred with an increased incidence in male and female mice receiving C.I. Pigment Red 3. Synonyms: 2-Naphthalenol, 1-((4-methyl-2-nitrophenyl)azo)-; Calcotone Toluidine Red YP; Fast Red A; Pigment Scarlet R; Recolite Fast Red RBL; Sengale Light Red B

Journal Article↗
PubMed1991

NTP Toxicology and Carcinogenesis Studies of Titanocene Dichloride (CAS No. 1271-19-8) in F344/N Rats (Gavage Studies).

Titanocene dichloride is an organometallic compound composed of two cyclopentadienyl rings, titanium, and chloride. It is used as a cocatalyst in polymerization reactions. Toxicology and carcinogenesis studies were conducted by administering titanocene dichloride (greater than 98% pure) in corn oil by gavage to groups of F344/N rats for 14 days, 13 weeks, and 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and in Chinese hamster ovary cells. 14-Day and 13-Week Studies: In the 14-day studies, titanocene dichloride was administered at doses of 0, 65, 125, 250, 500, or 1,000 mg/kg. All high-dose rats and four of the five male and two of the five female rats given 500 mg/kg died during the studies. A dose-related decrease in body weight gain was seen in rats given 125, 250, 500, and 1,000 mg/kg. Lesions related to chemical administration included hepatocellular necrosis, tubule necrosis in the kidney, erosions and ulcers of the glandular stomach, and hyperplasia of the forestomach epithelium. The 13-week studies were conducted by administering titanocene dichloride at doses of 0, 8, 16, 31, 62, or 125 mg/kg. One female rat in the 125 mg/kg dose group died from chemical toxicity during the fourth week of the studies. Body weight gain was lower in rats given 62 or 125 mg/kg than in control groups. Treatment-associated histopathologic lesions were seen in the stomachs of high-dose males and all groups of females given titanocene dichloride. These lesions included hyperplasia and metaplasia of the glandular stomach and hyperplasia and hyperkeratosis of the forestomach. Body Weight and Survival in the 2-Year Studies: The doses selected for the 2-year studies in rats (0, 25, and 50 mg/kg) were based on the potentially life-threatening nature of the glandular stomach lesions and the decreased body weight gain compared to controls seen in the 62 and 125 mg/kg dose groups in the 13-week studies. The final mean body weights of high-dose males and females were 91% and 89% of controls, respectively. The 2-year survival rates for males in the control, low-, and high-dose groups were 41/60, 30/60, and 24/60; survival rates for female rats were 37/60, 30/61, and 31/60. Nonneoplastic and Neoplastic Effects in the 2-Year Studies: The principal toxic effects associated with the administration of titanocene dichloride for 2 years occurred in the stomach. The lesions in the stomach were seen at the 15-month interim evaluations and were similar to, but less severe than, those observed at 2 years. The lesions included focal erosions of the glandular mucosa with an associated inflammatory response, hyperplasia and metaplasia of the epithelium of the fundic glands, and fibrosis of the lamina propria and submucosa. Forestomach lesions included focal acanthosis (hyperplasia) and hyperkeratosis of the stratified squamous epithelium. Squamous cell papillomas of the forestomach were seen in four low-dose males, one high-dose male, one low-dose female, and two high-dose females; none were observed in controls. A squamous cell carcinoma of the forestomach occurred in one low-dose male and a benign basosquamous tumor occurred in one high-dose male. Accumulations of macrophages with blue-gray pigment believed to contain titanium were present in many organs of dosed rats including the gastrointestinal tract, liver, lung, and lymph nodes. A dose-related increase in the incidence of inflammation of the nasal mucosa and lung also occurred and was attributed to reflux and/or regurgitation and aspiration of gavage solution due to the severe stomach lesions. Genetic Toxicology: Titanocene dichloride was mutagenic in Salmonella typhimurium strain TA100 in the absence of exogenous metabolic activation (S9); it was not mutagenic in TA100 with S9, nor was it mutagenic in TA1535, TA1537, or TA98 with or without S9. Titanocene dichloride did not induce sister chromatid exchanges or chromosomal aberrations in Chinese hamster ovary cells, with or without S9. Conclusions: Under the conditions of these 2-year gavage studies, there was equivocal, there was equivocal evidence of carcinogenic activity of titanocene dichloride in male F344/N rats based on a marginal increase in the incidence of forestomach squamous cell papillomas, squamous cell carcinoma, and basosquamous tumor benign. There was equivocal evidence of carcinogenic activity of titanocene dichloride in female F344/N rats based on a marginal increase in the incidence of forestomach squamous cell papillomas. Nonneoplastic lesions associated with the administration of titanocene dichloride for up to 2 years included erosions and inflammation of the gastric mucosa, hyperplasia and metaplasia of the fundic glands with fibrosis of the lamina propria in the glandular stomach, and acanthosis (hyperplasia) and hyperkeratosis of the forestomach epithelium. Synonyms: Titanium ferrocene; biscyclopentadienyltitanium dichloride; dichlorodi-p-cyclopentadienyltitanium; dichlorobis(h5-2,4-cyclopentadien-1-yl)titanium; dicyclopentadienyltitanium dichloride; dichlorodicyclopentadienyltitanium; dichlorotitanocene; dicyclopentadienyldichlorotitanium; dichlorobis(p-cyclopentadienyl)titanium; bis (h5-cyclopentadienyl) titanium dichloride; dichlorobis(h5-cyclopentadienyl)titanium; dichlorobiscyclopentadienyl titanium; dichlorobis(1,3-cyclopentadiene)titanium; bis(cyclopentadienyl)dichlorotitanium

Journal Article↗
PubMed1992

NTP Toxicology and Carcinogenesis Studies of Monochloroacetic Acid (CAS No. 79-11-8) in F344/N Rats and B6C3F1 Mice (Gavage Studies).

Monochloroacetic acid, a colorless crystalline material, is used as a postemergence contact herbicide and as an intermediate in the synthesis of other organic compounds. Toxicology and carcinogenicity studies were conducted by administering monochloroacetic acid (99% pure) in deionized water by gavage to groups of F344/N rats and B6C3F1 mice of each sex once daily, 5 days per week for 16 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, mouse lymphoma L5178Y cells, Chinese hamster ovary cells, and Drosophila melanogaster. 16-Day Studies: Groups of five rats of each sex received 0, 7.5, 15, 30, 60, or 120 mg monochloroacetic acid/kg body weight. Doses administered to mice were 0, 15, 30, 60, 120, or 240 mg/kg to groups of five males and 0, 30, 60, 120, 240, or 480 mg/kg to groups of five females. One of five male rats given 120 mg/kg died during the studies. Clear nasal discharge, lacrimation, or both, were observed in all groups of male and female rats receiving monochloroacetic acid. No compound-related gross lesions were observed in rats. All male mice given 240 mg/kg and all females given 240 or 480 mg/kg died during the studies. Hypoactivity, piloerection, ataxia, and lacrimation were observed in mice given 240 or 480 mg/kg. No compound-related gross lesions were observed in mice at necropsy. 13-Week Studies: Groups of 20 rats of each sex received 0, 30, 60, 90, 120, or 150 mg/kg monochloroacetic acid, and groups of 20 mice of each sex received doses of 0, 25, 50, 100, 150, or 200 mg/kg. Three to five animals in each dose group were killed at weeks 4 and 8 for the evaluation of hematology parameters. Compound-related deaths occurred in rats in the three highest dose groups (all males given 120 or 150 mg/kg, 9/10 males given 90 mg/kg, and all females given 90 to 150 mg/kg) and in mice given 200 mg/kg (all males and 2/10 females). Final mean body weights of surviving rats and mice receiving monochloroacetic acid were similar to those of controls. In rats, dose-related increases in blood urea nitrogen, alanine aminotransferase, and aspartate aminotransferase levels were observed, and relative liver and kidney weights were elevated. There were no compound-related changes in the various hematologic or clinical pathology parameters in mice. A dose-related increase in the incidence and severity of cardiomyopathy was observed in male and female rats receiving monochloroacetic acid, and hepatocellular cytoplasmic vacuolization was observed in the high-dose mice that died during the studies. 2-Year Studies: Based on the mortality and compound-related histopathologic lesions observed in the 13-week studies, doses selected for the 2-year studies of monochloroacetic acid were 0, 15, or 30 mg/kg, administered to groups of 70 rats of each sex, and 0, 50, or 100 mg/kg, administered to groups of 60 mice of each sex. Interim evaluations were conducted on 10 rats per dose group after 6 months of treatment with monochloroacetic acid and on seven rats per dose group after 15 months of treatment. Body Weight and Survival in the 2-Year Studies: Mean body weights of low- and high-dose female and low-dose male rats receiving monochloroacetic acid were within 10% of those of controls throughout the studies; however, after week 30, the mean body weights of high-dose male rats were 4% to 8% less than those of controls. In mice, the mean body weights of dosed males were similar to controls, but those of low- and high-dose females were 6% to 10% less than control values after week 52. Survival of high-dose male and dosed female rats and high-dose male mice was significantly lower than that of controls (male rats: control, 27/53; low-dose, 21/53; high-dose, 16/53; female rats: 37/53; 19/53; 26/53; male mice: 46/60; 39/60; 21/60; female mice: 42/60; 40/60; 44/60). Neoplasms and Nonneoplastic Lesions in the 2-Year Studies: There was no compound-related increase in the incidence of neoplasms or nonneoplastic lesions in rats given monochloroacetic acid for 2 years. The incidence of uterine stromal polypss. The incidence of uterine stromal polyps in low- and high-dose female rats was slightly higher than that in controls (2/60; 7/57; 10/60). However, the incidence in the controls was unusually low, and those in the dosed groups were well within the range for NTP historical controls (mean: 21%, range: 10%-38%). Further, because the only malignant stromal neoplasm occurred in a control animal, the polyps were not considered to be related to the administration of monochloroacetic acid. Similarly, there was no monochloroacetic acid-related increase in the incidence of neoplasms in male or female mice, and malignant lymphoma occurred with a significant negative trend in dosed female mice. Increases in the incidence of inflammation of the mucosa of the nasal passages, respiratory epithelial metaplasia of the olfactory epithelium of the nose, and focal squamous cell hyperplasia of the forestomach occurred in dosed male and female mice. Genetic Toxicology: Monochloroacetic acid was not mutagenic in Salmonella typhimurium strains TA100, TA1535, TA1537, or TA98, with or without exogenous metabolic activation (S9). It induced trifluorothymidine resistance in L5178Y cells in the absence of S9 and induced sister chromatid exchanges without S9 in Chinese hamster ovary cells. Monochloroacetic acid did not induce a significant increase in chromosomal aberrations in Chinese hamster ovary cells, with or without S9. Monochloroacetic acid administered in feed was negative for the induction of sex-linked recessive lethal mutations in germ cells of male Drosophila melanogaster; however, when it was administered by injection, the results were equivocal. Conclusions: Under the conditions of these 2-year gavage studies, there was no evidence of carcinogenic activity for monochloroacetic acid in male or female F344/N rats given 15 or 30 mg/kg. There was no evidence of carcinogenic activity for monochloroacetic acid in male or female B6C3F1 mice given 50 or 100 mg/kg. Monochloroacetic acid administration was associated with inflammatory lesions of the nasal mucosa, metaplasia of the olfactory epithelium, and squamous cell hyperplasia of the forestomach in male and female mice. Synonyms: Chloroacetic acid, a-chloroacetic acid, chloroethanoic acid

Journal Article↗
PubMed1991

NTP Toxicology and Carcinogenesis Studies of Probenecid (CAS No. 57-66-9) in F344/N Rats and B6C3F1 (Gavage Studies).

Probenecid is a white crystalline solid commonly used as a uricosuric agent in the treatment of gout. Because of its inhibitory effects on renal tubule transport processes, probenecid is also used as a therapeutic adjunct to enhance blood levels of penicillin and its action. Toxicology and carcinogenicity studies were conducted by administering probenecid (>99% pure) in corn oil by gavage to groups of F344/N rats and B6C3F1 mice of each sex once daily, 5 days per week in 14-day, 13-week, and 2-year studies. Genetic toxicology studies were conducted in Salmonella typhimurium and Chinese hamster ovary cells. 14-Day Studies: Doses used in the 14-day studies for both rats and mice were 0, 200, 400, 800, 1,600, or 3,200 mg/kg. Of the animals receiving 3,200 mg/kg, all rats, all female mice, and two of five male mice died during the studies. No deaths occurred among the other dose groups. There was a significant reduction in body weight gain in male and female rats receiving 1,600 mg/kg and in female rats receiving 800 mg/kg. No gross lesions were attributed to probenecid administration in rats or mice of either sex. 13-Week Studies: Doses used in the 13-week studies were 0, 50, 100, 200, 400, or 800 mg/kg for rats and 0, 100, 200, 400, 800, or 1,600 mg/kg for mice. No rats died during the 13-week studies. In mice, 5 of 10 males and 3 of 10 females receiving 1,600 mg/kg and 1 of 10 males receiving 800 mg/kg died during the study. Significant reductions in body weight gain occurred in male rats administered 800 mg/kg, male mice administered 1,600 mg/kg, and female mice administered 800 or 1,600 mg/kg. All dose groups of male rats and all groups of female rats receiving 100 mg/kg or more showed significant increases in absolute and/or relative liver weights compared to control groups. This change was also seen in mice receiving 200 mg/kg and greater, except female mice in the 400 mg/kg group. No compound-related lesions occurred in rats or mice of either sex. Based on compound-related deaths and suppression of body weight gains observed at higher doses in the 13-week studies, doses of 0, 100, and 400 mg/kg were used for the 2-year studies in rats and mice. These doses were administered once daily, 5 days a week for up to 103 weeks to groups of 50 males or 50 females of each species. Body Weight and Survival in the 2-Year Studies: The mean body weight of high-dose female rats was 10% to 20% lower than that of controls throughout the studies. Mean body weights for all other dosed rats and for all dosed mice were similar to those of controls throughout the 2-year studies. Survival of high-dose male rats and high-dose and low-dose male mice was significantly lower than that of controls. Survival rates after 2 years were: male rats--control, 37/50; 100 mg/kg, 34/50; 400 mg/kg, 22/50; female rats--24/50; 35/50; 19/50; male mice--38/50; 23/50; 24/50; female mice--32/49; 32/49; 32/50. Neoplasms and Nonneoplastic Lesions in the 2-Year Studies: No chemical-related histopathologic toxic effects or increased incidence of tumors attributable to probenecid were observed in male or female rats receiving probenecid by corn oil gavage for up to 2 years. Mammary gland fibroadenomas and combined thyroid C-cell adenomas or carcinomas exhibited significant negative trends in female rats. These decreased tumor rates were associated with lower body weights. The incidence of adrenal medullary pheochromocytomas was significantly decreased in high-dose male rats. No compound-related increase in nonneoplastic lesions was observed in rats of either sex. No compound-related neoplastic effects were observed in male mice. In high-dose female mice, there were significant increases in the incidences of hepatocellular adenomas (3/48; 2/49; 14/49), but there was no corresponding increase in carcinomas (2/48; 2/49; 3/49). Treatment-related increased incidences of ovarian abscesses in female mice were causally related to Klebsiella species infection rather than directly related to chemical administration. Genetic Toxicology: Probenecid was not mutagenic in Salmonenot mutagenic in Salmonella typhimurium strain TA100, TA1535, TA1537, or TA98 with or without metabolic activation. In cytogenetic tests with Chinese hamster ovary cells, probenecid induced sister chromatid exchanges in the absence, but not in the presence of S9 activation. No induction of chromosomal aberrations was observed with or without S9. Conclusions: Under the conditions of these 2-year gavage studies, there was no evidence of carcinogenic activity of probenecid for male or female F344/N rats receiving 100 or 400 mg/kg in corn oil. There was no evidence of carcinogenic activity of probenecid for male B6C3F1 mice given 100 or 400 mg/kg probenecid in corn oil. There was some evidence of carcinogenic activity of probenecid for female B6C3F1 mice based on an increased incidence of hepatocellular adenomas. Synonyms: 4-[(Dipropylamino)sulfonyl]benzoic acid; p-(dipropylsulfamoyl)benzoic acid; p-(dipropylsulfamyl)benzoic acid Trade Names: Benacen; Benemid; Benemide; Benn; Probalan; Probecid; Proben; Probenid; Robenecid; Uricocid

Journal Article↗
PubMed1993

NTP Toxicology and Carcinogenesis Studies of Acetaminophen (CAS No. 103-90-2) in F344 Rats and B6C3F1 Mice (Feed Studies).

Acetaminophen is a widely consumed analgesic found in several nonprescription pharmaceuticals. Toxicology and carcinogenesis studies were conducted by administering acetaminophen (purity >99%) in feed to groups of F344/N rats and B6C3F1 mice of each sex for 14 days, 13 weeks, and 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Chinese hamster ovary cells. 14-DAY STUDIES: Rats were fed diets containing 0, 800, 1,600, 3,100, 6,200, or 12,500 ppm acetaminophen, and mice were fed diets containing 0, 250, 500, 1,000, 2,000, or 4,000 ppm acetaminophen. There were no deaths among any groups during the study; the final mean body weight of male rats that received 12,500 ppm was significantly lower than that of the controls. Final mean body weights of male and female mice and female rats that received acetaminophen were similar to those of the controls. Feed consumption by male and female rats that received 12,500 ppm acetaminophen was lower than that of the controls; feed consumption by all other exposed groups was higher than that of the controls. 13-WEEK STUDIES: Rats and mice were fed diets containing 0, 800, 1,600, 3,200, 6,200, 12,500, or 25,000 ppm acetaminophen. Two male and two female rats, and one male and one female mouse that received 25,000 ppm, and two male mice that received 12,500 ppm died from acetaminophen-related toxicity before the end of the studies. Final mean body weights of male and female rats and mice that received 12,500 or 25,000 ppm were lower than those of the controls. The patterns of feed consumption and reduced body weights that occurred among rats and mice that received diets containing 12,500 or 25,000 ppm were indicative of poor feed palatability. Acetaminophen-related lesions were observed in the liver (necrosis, chronic active inflammation, hepatocytomegaly), kidney (tubule cast, tubule necrosis, tubule regeneration), reproductive organs (atrophy of testis, ovary, and uterus), thymus and lymph nodes (lymphoid depletion) of rats that received 25,000 ppm, and of the live (chronic active inflammation, hepatocytomegaly) and testis (atrophy) of male rats receiving 12,500 ppm. Compound-related lesions in mice were found in the liver (hepatocytomegaly, focal calcification, pigmentation, necrosis) of males that received 6,200, 12,500, or 25,000 ppm and females that received 12,000 or 25,000 ppm. Dose selection for the 2-year studies was based on reduced body weights and the liver lesions observed in rats and mice at 12,500 and 25,000 ppm. 2-YEAR STUDIES: Diets containing 0, 600, 3,000, or 6,000 ppm acetaminophen were given continuously to groups of 60 rats and mice of each sex for up to 104 weeks. After 65 weeks of exposure, 10 animals from each group were evaluated for histopathology and for hematology, urinalysis, and clinical chemistry parameters. Survival and mean body weights of rats that received acetaminophen were similar to those of the controls throughout the study. The average severity of nephropathy was increased in exposed male and female rats. In males this was associated with an increased incidence of parathyroid hyperplasia (renal hyperparathyroidism). The incidence of focal renal tubule hyperplasia was also increased in exposed male rats. The incidence of mononuclear cell leukemia was increased in exposed female rats and was significantly increased in the 6,000 ppm group (9/50; 17/50; 15/50; 24/50). Survival of exposed and control mice was similar throughout the study. Mean body weights of mice that received acetaminophen were generally lower than those of the controls throughout the study. Although the incidence of thyroid follicular cell hyperplasia increased with dose among groups of exposed male and female mice, there was no increase in the incidence of follicular cell neoplasms. Renal tubule hyperplasia occurred in one low-dose and two high-dose males and a renal tubule adenoma was present in one low-dose and one high-dose male. GENETIC TOXICOLOGY: Acetaminophen was not mutagenic in Salmonella typhimurium strains TA100, TA1535, TA1537, or TA98 witr TA98 with or without S9. In cytogenetic tests with Chinese hamster ovary cells, acetaminophen induced sister chromatid exchanges and chromosomal aberrations in both the presence and absence of S9. CONCLUSIONS: Under the conditions of these 2-year feed studies, there was no evidence of carcinogenic activity of acetaminophen in male F344/N rats that received 600, 3,000, or 6,000 ppm. There was equivocal evidence of carcinogenic activity of acetaminophen in female F344/N rats based on increased incidences of mononuclear cell leukemia. There was no evidence of carcinogenic activity of acetaminophen in male and female B6C3F1 mice that received 600, 3,000, or 6,000 ppm. Nonneoplastic lesions associated with exposure to acetaminophen included increased severity of nephropathy and increased incidences of renal tubule hyperplasia and parathyroid hyperplasia in male rats, increased severity of nephropathy in female rats, and increased incidences of thyroid follicular cell hyperplasia in male and female mice. Synonyms: 4-Hydroxyacetanilide, N-Acetyl-p-aminophenol, Paracetamol

Journal Article↗
PubMed1990

NTP Toxicology and Carcinogenesis Studies of Sodium Fluoride (CAS No. 7681-49-4)in F344/N Rats and B6C3F1 Mice (Drinking Water Studies).

Sodium fluoride is a white, crystalline, water-soluble powder used in municipal water fluoridation systems, in various dental products, and in a variety of industrial applications. Toxicology and carcinogenesis studies were conducted with F344/N rats and B6C3F1 mice of each sex by incorporating sodium fluoride into the drinking water in studies lasting 14 days, 6 months, and 2 years. In addition, genetic toxicology studies were performed with Salmonella typhimurium, with mouse L5178Y cells, and with Chinese hamster ovary cells. 14-Day Studies: Rats and mice received sodium fluoride in drinking water at concentrations as high as 800 ppm. (Concentrations are expressed as sodium fluoride; fluoride ion is 45% of the sodium salt by weight.) In the high-dose groups, 5/5 male and 5/5 female rats and 2/5 male mice died; one female rat was given 400 ppm in the drinking water also died before the end of the studies. No gross lesions were attributed to sodium fluoride administration. 6-Month Studies: Rats received concentrations of sodium fluoride in drinking water as high as 300 ppm, and mice as high as 600 ppm. No rats died during the studies; however, among the mice, 4/9 high-dose males, 9/11 high-dose females, and 1/8 males in the 300 ppm group died before the end of the studies. Weight gains were less than those of controls for rats receiving 300 ppm and mice receiving 200 to 600 ppm. The teeth of rats and mice receiving the higher doses of sodium fluoride were chalky white and chipped or showed unusual wear patterns. Mice and male rats given the higher concentrations had microscopic focal degeneration of the enamel organ. Rats receiving 100 or 300 ppm sodium fluoride had minimal hyperplasia of the gastric mucosa of the stomach, and one high-dose rat of each sex had an ulcer. Acute nephrosis and/or lesions in the liver and myocardium were observed in mice that died early, and minimal alterations in bone growth/remodeling were observed in the long bones of mice receiving sodium fluoride at concentrations of 50 to 600 ppm. The sodium fluoride concentrations selected for the 2-year studies in both rats and mice were 0, 25, 100, and 175 ppm in the drinking water. These concentrations were selected based on the decreased weight gain of rats at 300 ppm and of mice at 200 ppm and above, on the incidence of gastric lesions in rats at 300 ppm in the 6-month studies, and on the absence of significant toxic effects at sodium fluoride concentrations as high as 100 ppm in an earlier 2-year study. Body Weights and Survival in the 2-Year Studies: Mean body weights of dosed and control groups of rats and mice were similar throughout the 2-year studies. Survival of rats and mice was not affected by sodium fluoride administration. Survival rates after 2 years were: male rats-control, 42/80; 25 ppm, 25/51; 100 ppm, 23/50; 175 ppm, 42/80; female rats-59/80; 31/50; 34/50; 54/81; male mice-58/79; 39/50; 37/51; 65/80; female mice-53/80; 38/52; 34/50; 52/80. Neoplastic and Nonneoplastic Effects in the 2-Year Studies: The teeth of rats and mice has a dose-dependent whitish discoloration, and male rats had an increased incidence of tooth deformities and attrition leading on occasion to malocclusion. The teeth of male and, to a lesser degree, female rats had areas of microscopic dentine dysplasia and degeneration of ameloblasts. Dentine dysplasia occurred in both dosed and control groups of male and female mice; the incidence of this lesion was significantly greater in high-dose than in control male mice. Osteosclerosis of long bones was increased in female rats given drinking water containing 175 ppm sodium fluoride. No other significant nonneoplastic lesions in rats or mice appeared related to sodium fluoride administration. Osteosarcomas of bone were observed in 1/50 male rats in the 100 ppm group and in 3/80 male rats in the 175 ppm group. None were seen in the control or 25 ppm dose groups. One other 175 ppm male rat had an extraskeletal osteosarcoma arising in the subcutaneous tissue. Osteosarcomas occur in historical control male rats at an incian incidence of 0.5% (range 0-6%). The historical incidence is not directly comparable with the incidences observed in this study because examination of bone was more comprehensive in the sodium fluoride studies than in previous NTP studies of other chemicals, and the diet used in previous studies was not controlled for fluoride content. In the current study, although the pairwise comparison of the incidence in the 175 ppm group versus that in the controls was not statistically significant, osteosarcomas occurred with a statistically significant dose-response trend, leading to the conclusion that a weak association may exist between the occurrence of these neoplasms and the administration of sodium fluoride. No other neoplastic lesions in rats or mice were considered possibly related to chemical administration. Genetic Toxicology: Sodium fluoride was negative for gene mutation induction in Salmonella typhimurium strains TA100, TA1535, TA1537, and TA98 with and without S9. In two laboratories, sodium fluoride was tested for induction of trifluorothymidine resistance in mouse L5178Y lymphoma cells; results were positive both with and without S9. Sodium fluoride was tested for cytogenetic effects in Chinese hamster ovary (CHO) cells in two laboratories. In the first laboratory, the sister chromatid exchange (SCE) test was negative with and without S9, and the chromosomal aberration (Abs) test was positive in the absence of S9; in the second laboratory, the SCE test was positive with and without S9, but no induction of Abs was observed. The laboratory that reported a negative result for Abs tested at doses below that shown to be positive at the other laboratory. Similarly, the positive SCE result was obtained at a higher dose and longer harvest time than used by the laboratory reporting the negative SCE response. Conclusions: Under the conditions of these 2-year dosed water studies, there was equivocal evidence of carcinogenic activity of sodium fluoride in male F344/N rats, based on the occurrence of a small number of osteosarcomas in dosed animals. "Equivocal evidence" is a category for uncertain findings defined as studies that are interpreted as showing a marginal increase of neoplasms that may be related to chemical administration. There was no evidence of carcinogenic activity in female F344/N rats receiving sodium fluoride at concentrations of 25, 100, or 175 ppm (11, 45, or 79 ppm fluoride) in drinking water for 2 years. There was no evidence of carcinogenic activity of sodium fluoride in male or female mice receiving sodium fluoride at concentrations of 25, 100, or 175 ppm in drinking water for 2 years. Dosed rats had lesions typical of fluorosis of the teeth and female rats receiving drinking water containing 175 ppm sodium fluoride had increased osteosclerosis of long bones.

Journal Article↗
PubMed1991

NTP Toxicology and Carcinogeneis Studies of Sodium Azide (CAS: 26628-22-8) in F344 Rats (Gavage Studies).

Sodium azide is a white crystalline solid used in the manufacture of the explosive lead azide. It is the principal chemical used to generate nitrogen gas in automobile safety airbags and airplane escape chutes and is a broad-spectrum biocide used in both research and agriculture. Toxicology and carcinogenicity studies were conducted by administering sodium azide (greater than 99% pure) in distilled water by gavage to groups of male and female F344/N rats once daily, 5 days per week for 14 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Chinese hamster ovary cells. 14-Day Studies: Rats received 0, 5, 10, 20, 40, or 80 mg/kg sodium azide. All male and female rats receiving 40 or 80 mg/kg and two of five female rats receiving 20 mg/kg died during the first week of the studies. Clinical findings of toxicity included lethargy and inactivity. No grossly observable lesions were present in any of the dose groups. 13-Week Studies: Rats received 0, 1.25, 2.5, 5, 10, or 20 mg/kg sodium azide. Seven of 9 males and all 10 females receiving 20 mg/kg died before the end of the studies. Final mean body weights of treated rats were within 10% of those of the controls. Compound-related clinical findings of toxicity in the 20 mg/kg dose groups included lethargy and labored breathing. Histopathologic lesions induced by sodium azide were limited to the brain (necrosis of the cerebrum and thalamus) and lung (congestion, hemorrhage, and edema), and were observed in rats receiving 20 mg/kg that died during the studies. Body Weights, Feed Consumption, and Survival in the 2-Year Studies: Because compound-related deaths were observed in the groups receiving 20 mg/kg in the 13-week studies, lower dose levels were used in the 2-year studies. Two-year studies were conducted by administering 0, 5, or 10 mg/kg sodium azide to groups of 60 male and 60 female rats. Dose-related depression in mean body weight was observed throughout the study period. Mean feed consumption values in low- and high-dose groups were lower than control values. Survival of high-dose rats of each sex was significantly (P<0.05) lower than controls (males-control, 24/60; low-dose, 27/60; high-dose, 9/60; females-37/60; 43/60; 21/59). The reduced survival was attributed to brain necrosis and cardiovascular collapse induced by sodium azide. Neoplastic and Nonneoplastic Effects in the 2-Year Studies: There were no compound-related increases in incidences of neoplasms in rats. Significantly decreased incidences were observed for certain neoplasms, including mononuclear cell leukemia in male rats (control, 33/60; low-dose, 28/60; high-dose, 14/60), adrenal gland pheochromocytoma in male rats (26/55; 16/56; 6/54), mammary gland fibroadenoma in female rats (20/60; 11/60; 8/59), and pituitary gland neoplasms in female rats (37/60; 28/60; 17/59). These decreases reflected to some extent, but could not be attributed solely to, the reduced survival of the high-dose groups. Compound-related nonneoplastic brain lesions (necrosis of the cerebrum and thalamus) were observed at significantly (P<0.001) increased incidences in high-dose male and female rats. The increased incidence of lung congestion observed in this dose group was considered due to cardiovascular collapse secondary to brain necrosis. Genetic Toxicology: Sodium azide was mutagenic in Salmonella typhimurium strains TA100 and TA1535, with or without exogenous metabolic activation (S9); it was not mutagenic in strain TA1537 or TA98. In cytogenetic tests with Chinese hamster ovary cells, sodium azide induced sister chromatid exchanges, but not chromosomal aberrations, in the presence and the absence of S9. Conclusions: Under the conditions of these 2-year gavage studies, there was no evidence of carcinogenic activity of sodium azide in male or female F344/N rats administered 5 or 10 mg/kg. Sodium azide induced necrosis in the cerebrum and the thalamus of the brain in both male and female rats. Synonyms: Azide, Azium, Smite

Journal Article↗
PubMed1991

NTP Toxicology and Carcinogenesis Studies of dl-Amphetamine Sulfate (CAS No. 60-13-9) in F344/N Rats and B6C3F1 Mice (Feed Studies).

dl-Amphetamine sulfate is used for the treatment of narcolepsy in adults and behavioral syndromes in children. Toxicology and carcinogenesis studies were conducted by administering dl-amphetamine sulfate (USP grade) in feed to groups of F344/N rats and B6C3F1 mice of each sex for 14 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Chinese hamster ovary (CHO) cells. 14-Day Studies: The chemical was administered at dietary concentrations of 0, 47, 94, 188, 375, or 750 ppm for rats and 0, 125, 250, 500, 1,000, or 2,000 ppm for mice. Decreased body weight gain was seen at the higher concentrations, but no chemical-related deaths or toxic lesions were observed. 13-Week Studies: The chemical was administered at dietary concentrations of 0, 47, 94, 188, 375, or 750 ppm for rats and 0, 125, 250, 500, 1,000, or 2,000 ppm for mice. None of the rats died, but 6/10 male mice and 7/10 female mice that received 2,000 ppm, 3/10 male mice that received 1,000 ppm, and 8/10 male mice that received 500 ppm died before the end of the studies. Decreased body weight gain and hyperactivity were seen in dosed rats and mice. Final body weights of rats receiving 188 ppm or more were 62% to 89% those of controls, and final body weights of mice receiving 250 ppm or more were 70% to 86% those of controls. There were no lesions that were considered to be a primary effect of the chemical. Based on decreased body weight gain and hyperactivity in the 13-week studies, 2-year studies were conducted by feeding diets containing 0, 20 or 100 ppm dl-amphetamine sulfate to groups of 50 rats or 50 mice of each sex. Body Weights and Survival in the 2-Year Studies: No significant differences in survival were observed between any groups of rats or mice (male rats: control, 30/50; low dose, 31/50; high dose, 33/50; female rats: 33/50; 42/50; 37/50; male mice: 48/50; 48/50; 49/50; female mice: 35/50; 36/50; 44/50). Final body weights of dosed rats and mice were decreased relative to those of controls. Final body weights were 92% and 86% those of controls for low- and high-dose male rats, 89% and 70% those of controls for low- and high-dose female rats, 85% and 72% those of controls for low- and high-dose male mice, and 81% and 66% those of controls for low- and high-dose female mice. Hyperactivity was observed in all dosed groups. Feed consumption was similar among control and exposed groups with the exception of high-dose female rats (84% of controls) and high-dose male mice, for which hyperactivity resulted in scattering of feed and overestimation of feed consumption. The average amount of dl-amphetamine sulfate consumed per day was estimated to be 1 or 5 mg/kg for low- and high-dose rats, 4 or 30 mg/kg for low- or high-dose male mice, and 3 or 19 mg/kg for low- or high-dose female mice. Nonneoplastic and Neoplastic Effects in the 2-Year Studies: Myelofibrosis, cataracts, and retinal atrophy in female rats, and ovarian atrophy in female mice occurred in a larger proportion of high-dose animals than in controls. Dose-related increases in neoplasms did not occur in rats or mice receiving amphetamine. The administration of dl-amphetamine sulfate was associated with decreases in the incidence of total neoplasms and in the incidences of certain site-specific neoplasms, including pheochromocytomas of the adrenal gland in male rats (23/49, 15/44, 7/50), fibroadenomas of the mammary gland in female rats (21/50, 11/50, 2/50), adenomas of the anterior pituitary gland in male and female rats and female mice (male rats: 15/49, 15/48, 9/49; female rats: 31/50, 24/48, 19/50; female mice: 12/49, 6/49, 1/46), endometrial stromal polyps of the uterus of female rats (10/50, 6/50, 3/50), adenomas or carcinomas (combined) of the liver in male and female mice (male: 14/50, 12/50, 2/50; female: 5/50, 1/50, 1/47), adenomas of the harderian gland in male and female mice (male: 4/50, 2/50, 0/50; female: 5/50, 2/50, 0/47), and adenomas or carcinomas (combined) of the lung in male and female mice (male: 8/50, 3/50, 4/50; female: 8/50, 6/50 (combined) of the lung in male and female mice (male: 8/50, 3/50, 4/50; female: 8/50, 6/50, 1/47). Genetic Toxicology: dl-Amphetamine sulfate was tested for induction of gene mutations in Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 with and without exogenous metabolic activation (S9); the only response observed was in strain TA98 in the presence of S9, and it was judged to be equivocal. No induction of sister chromatid exchanges or chromosomal aberrations occurred in Chinese hamster ovary cells treated with amphetamine sulfate in either the presence or the absence of S9. Conclusions: Under the conditions of these 2-year feed studies, there was no evidence of carcinogenic activity of dl-amphetamine sulfate for male or female F344/N rats or male or female B6C3F1 mice fed 20 or 100 ppm. The administration of dl-amphetamine sulfate was associated with decreased body weight. There were decreased incidences of total neoplasms in dosed rats and mice, of adrenal pheochromocytomas in male rats, of mammary gland fibroadenomas and uterine polyps in female rats, of pituitary gland adenomas in male and female rats and female mice, and of harderian gland adenomas, liver neoplasms, and lung neoplasms in male and female mice. Synonyms: (&plusmn;)-amphetamine sulfate; (&plusmn;)-2-amino-1-phenylpropane sulfate; amphetamine sulfate; deoxynorephedrine; desoxynorephedrine; (&plusmn;)-a-methylphenethylamine sulfate; (&plusmn;)-phenisopropylamine sulfate; b-phenyl isopropylamine Trade Names: Acedron; Adipan; Adiparthrol; Aketdrin; Aktedrin; Alentol; Amfetamina; Amphaetamin; Amphamed; Amphatamin; Amphate; Amphedrine; Amphetaminum; Amphezamin; Amphoids-S; Anara; Anfetamina; Anorexine; Astedin; Benzafinyl; Benzamphetamine; Benzebar; Benzedrina; Benzedryna; Benzolone; Benzpropamine;Betafen; Betaphen; Bluzedrin; Centramina; Didrex; Dietamine; Durophet; Elastonin; Elastonon; Euphobine; Euphodine; Euphodyn; Fabedrine; Fenamin; Fenara; Fenedrin; Fenopromin; Halloo-Wach; Ibiozedrine; Isamin; Isoamin; Isoamyne; Isomyn; Leodrin; Levonor; Linampheta; Mecodrin; Mimetina; Monetamine; Noclon; Norephedrane; Norphedrane; Novydrine; Oktedrin; Oraldrina; Ortenal; Orthedrin; Percomon; Pharmamedrine; Pharmedrine; Phenamine; Phenedrine; Phenopromin; Phenpromin; Profamina; Profetamine; Propenyl; Propisamine; Psychedrine; Psychedryna; Psychedrinum; Psychoton; Racephen; Rhinalator; Sedolin; Simpamina; Simpamine; Simpatedrin; Stimulan; Sympametin; Sympamine; Sympatedrine; Synsatedrine; Theptine; Vapedrine; Weckamine; Zedrine Slang for Amphetamines: bennies; benzies; cartwheels; hearts; peaches; roses

Journal Article↗
PubMed1990

NTP Toxicology and Carcinogenesis Studies of Tetranitromethane (CAS No. 509-14-8) in F344/N Rats and B6C3F1 Mice (Inhalation Studies).

Tetranitromethane is a volatile contaminant formed during the manufacture of TNT and has been used as a rocket fuel and biochemical reagent. Toxicology and carcinogenesis studies were conducted in F344/N rats and B6C3F1 mice of each sex by whole body exposure to tetranitromethane vapor (greater than 99% pure), 6 hours per day, 5 days per week for 14 days, 13 weeks, or 2 years. Additional groups of male mice were exposed to tetranitromethane for evaluation at 1 year. Genetic toxicology studies were performed in Salmonella typhimurium and Chinese hamster ovary (CHO) cells. Fourteen-Day Studies: Exposure concentrations ranged from 2 to 25 ppm for rats and from 2 to 50 ppm for mice. All rats exposed to 25 ppm and all mice exposed at the top concentration of 50 ppm died by day 2; reduced survival was seen in mice exposed to 25 ppm and in rats exposed to 10 ppm. Pulmonary edema in rats and inflammation of the lung in mice were seen in those animals in the 25- and 50-ppm exposure groups examined microscopically. Thirteen-Week Studies: Exposure concentrations ranged from 0.2 to 10 ppm for rats and mice. No exposure-related deaths occurred in rats. The final mean body weight of rats exposed to 10 ppm was 16% lower than that of controls for males and 6% lower for females. Exposure-related histologic effects included squamous metaplasia of the respiratory epithelium of the nasal mucosa and chronic inflammation of the lung. No deaths of mice could be clearly related to exposure to tetranitromethane. The final mean body weights of mice exposed to 5 or 10 ppm were 5% or 12% lower than that of controls for males and 9% or 12% lower for females. Exposure-related histologic effects in mice included inflammation and squamous metaplasia of the respiratory epithelium of the nasal mucosa and hyperplasia of the bronchiolar epithelium. Based on the incidences and severity of lesions in the respiratory at the higher concentrations used in the 13-week studies, exposure concentrations chosen for the 2-year studies were 0, 2, and 5 ppm for groups of 50 rats of each sex and 0, 0.5, and 2 ppm for groups of 50 mice of each sex. Additional groups of 6 or 10 male mice were exposed at concentrations of 0, 0.5, or 2 ppm for 1 year. Body Weights and Survival in the Two-Year Studies: Mean body weights of male and female rats exposed to 5 ppm were approximately 5%-15% lower than those of controls after week 70. Survival of rats at 104 weeks was as follows: male: control, 18/50; 2 ppm, 17/50; 5 ppm, 4/50; female: 25/50; 34/50; 15/50; survival of rats at the top concentration was reduced due to neoplasia. Mean body weights of exposed mice were variable and ranged as much as 10% below those of controls during the second year of the studies. Survival of exposed male mice at 104 weeks was significantly lower than that of controls due to neoplasia (control, 37/50; 0.5 ppm, 26/50; 2 ppm, 15/50). Survival of female mice was not significantly affected by exposure to tetranitromethane (31/50; 28/50; 24/50). Neoplastic and Nonneoplastic Effects in the Two-Year Studies: Effects of exposure to tetranitromethane were limited to the respiratory tract. Hyperplasia of the alveolar and bronchiolar epithelium was observed at increased incidences in exposed rats. The incidence of alveolar/bronchiolar adenomas and carcinomas were markedly increased in exposed male and female rats, with carcinomas (many of which metastasized to other sites) occurring in nearly all rats exposed to the top concentration of 5 ppm (adenomas or carcinomas-- male: control, 1/50; 2 ppm, 33/50; 5 ppm, 46/50; female: 0/50; 22/50; 50/50). Many of the rats exposed to 5 ppm also had squamous cell carcinomas of the lung (male: 0/50; 1/50; 19/50; female: 0/50; 1/50; 12/50). Hyperplasia of the respiratory epithelium and chronic inflammation of the nasal mucosa were observed at increased incidences in exposed male and female rats. Squamous metaplasia of the respiratory epithelium was increased in exposed male rats. No neoplasms of the nasal passage were seen. In exposed mice, hyperplasia of the alveolar and br were seen. In exposed mice, hyperplasia of the alveolar and bronchiolar epithelium was observed at increased incidences. Alveolar/bronchiolar neoplasms, primarily carcinomas (many of which metastasized to other sites), were increased in exposed male and female mice (male: control, 12/50; 0.5 ppm, 27/50; 2 ppm, 47/50; female: 4/49; 24/50; 49/50). Chronic inflammation of the nasal mucosa and hyperplasia and squamous metaplasia of the respiratory epithelium of the nasal cavity occurred at increased incidences in female mice exposed to 2 ppm. No primary neoplasms of the nasal passage were observed in mice. Oncogene Analysis: DNA from 14/19 rat and 4/4 mouse lung neoplasms caused morphologic transformation after transfection into cultured NIH/3T3 fibroblasts. The transforming gene from both rat and mouse lung neoplasms was determined by Southern blot analysis to be an activated K-ras oncogene. Further studies showed a GC-->AT transition in the second base of the 12th codon of the K-ras oncogene. Genetic Toxicology: Tetranitromethane was mutagenic in S. typhimurium strains TA98, TA100, and TA1535 with and without exogenous metabolic activation (S9); no mutagenic activity was observed in TA1537 with or without S9. Chromosomal aberrations were observed in CHO cells treated in vitro with tetranitromethane in the presence of S9. Sister chromatid exchanges were induced in CHO cells in the absence of S9. Conclusions: Under the conditions of these 2-year inhalation studies, there was clear evidence of carcinogenic activity of tetranitromethane for male and female F344/N rats and male and female B6C3F1 mice, based on increased incidences of alveolar/bronchiolar neoplasms in both species and squamous cell carcinomas of the lung in rats. Chronic inflammation of the nasal mucosa was related to exposure in rats and female mice, and hyperplasia and squamous metaplasia of the respiratory epithelium were increased in exposed male rats. Synonym: TNM

Journal Article↗
PubMed1990

NTP Toxicology and Carcinogenesis Studies of a-Methylbenzyl Alcohol (CAS No. 98-85-1) in F344/N Rats and B6C3F1 Mice (Gavage Studies).

NTP Toxicology and Carcinogenesis studies of a-methylbenzyl alcohol (greater than 99% pure), a cosmetic ingredient and food flavoring agent, were conducted by administering the chemical in corn oil by gavage to groups of F344/N rats and B6C3F1 mice of each sex for 16 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, mouse lymphoma cells, and Chinese hamster ovary (CHO) cells. a-Methylbenzyl alcohol was nominated for study by the National Cancer Institute because of the potential for widespread human exposure. Sixteen-Day and Thirteen-Week Studies: The doses used in the 16-day studies for rats and mice ranged between 125 and 2,000 mg/kg. Six of 10 rats and all mice dosed at 2,000 mg/kg died. In addition, because 7/9 mice dosed at 1,000 mg/kg died, the doses selected for the 13-week studies for mice (47-750 mg/kg) were half those used for rats (93-1,500 mg/kg). In the 13-week studies, deaths of 1/10 male and 3/10 female rats dosed at 1,500 mg/kg were compound related; none of the mice died. Body weight gain was reduced in rats at 1,500 mg/kg; there were no significant histopathologic lesions in either rats or mice. The only compound-related effects were ataxia, labored breathing, and lethargy for up to 30 minutes after dosing in rats and mice given the two highest doses and increases in liver weight to body weight ratios for male rats given the three highest doses and for female rats at all doses. Based on the pattern of mortality and the effects on body weight gain in the short-term studies, doses of 375 and 750 mg/kg a-methylbenzyl alcohol were administered in corn oil by gavage, 5 days per week for 103 weeks, to groups of 50 rats and 50 mice of each sex. Two-Year Studies: Significant reduction in body weight gain commenced at weeks 20-30 in high dose male and female rats, and body weights were 20%-30% below those of vehicle controls at study termination. In the low dose groups, body weight reduction occurred only in male rats during the last 10 weeks of the study. After 80 weeks, 60% of the high dose rats and 80%-100% of the low dose and vehicle control rats were alive; thereafter, the number of deaths in the chemically exposed groups increased sharply so that, at the end of 2 years, final survival for vehicle control, low dose, and high dose rats was 35/50; 8/50; and 1/50 for males and 34/50, 25/50, and 11/50 for females. There were a large number of gavage accidents in these studies (1, 9, and 8 for male rats and 1, 4, and 14 for female rats), but these accidents did not contribute to the increase in mortality after week 80, as all but 4 of these occurred earlier. Mortality in the last quarter of the study was thought to be due to the effects of cumulative toxicity of a-methylbenzyl alcohol on a renal excretory system already compromised by aging. Renal nephropathy that commonly occurs during aging was found in all groups of rats, but the severity was greater in male rats dosed with a-methylbenzyl alcohol. In addition, a collection of nonneoplastic lesions (parathyroid hyperplasia, calcification of the heart and glandular stomach, and fibrous osteodystrophy of bone) was found in the dosed male rats; these lesions were probably secondary to mineral imbalance arising from renal dysfunction. Since survival was poor in low and high dose male and high dose female rats, the sensitivity of the study for detecting a carcinogenic effect in these groups was reduced. Despite this limitation, there were dose-related increases in the incidences of renal tubular cell adenomas or adenocarcinomas (combined) in male rats (vehicle control, 0/50; low dose, 2/50; high dose, 5/50). In addition, transitional cell papillomas of the urinary bladder were observed in one high dose male and two high dose female rats. In mice, a reduction in body weight gain was apparent in the high dose groups of males and females. Final survival rates in mice were similar among groups (male: 39/49; 40/50; 28/50; female: 41/50; 41/50; 38/50). No neoplastic or nonneoplastic lesions were attributed to a-methylbenzyl lesions were attributed to a-methylbenzyl alcohol administration in mice of either sex. Genetic Toxicology: a-Methylbenzyl alcohol was not mutagenic in S. typhimurium strains TA98, TA100, TA1535, or TA1537 when tested in the presence or absence of exogenous metabolic activation. a-Methylbenzyl alcohol produced a positive response without activation in the mouse L5178Y/TK+/- lymphoma assay for induction of trifluorothymidine resistance; it was not tested with activation. In cytogenetic tests with CHO cells, a-methylbenzyl alcohol induced chromosomal aberrations in the presence, but not the absence, of metabolic activation; no induction of sister chromatid exchanges was observed in CHO cells after exposure to a-methylbenzyl alcohol. Conclusions: Under the conditions of these 2-year gavage studies, there was some evidence of carcinogenic activityof a-methylbenzyl alcohol for male F344/N rats, as shown by increased incidences of renal tubular cell adenomas and adenomas or adenocarcinomas (combined). There was no evidence of carcinogenic activity for female F344/N rats administered 375 or 750 mg/kg. Renal toxicity characterized by severe nephropathy and related secondary lesions was observed in the dosed rats, and excessive mortality occurred during the last quarter of the studies. Poor survival reduced the sensitivity of the studies for detecting the presence of a carcinogenic response both in chemically exposed groups of male rats and in the high dose group of female rats. There was no evidence of carcinogenic activity of a-methylbenzyl alcohol for male or female B6C3F1 mice administered 375 or 750 mg/kg for 2 years. Synonyms: styrallyl alcohol; styralyl alcohol; a-methylbenzenemethanol; phenylmethylcarbinol; 1-phenethyl alcohol

Journal Article↗
PubMed1989

NTP Toxicology and Carcinogenesis Studies of Nalidixic Acid (CAS No. 389-08-2) in F344/N Rats and B6C3F1 Mice (Feed Studies).

Nalidixic acid is an antimicrobial agent to treat bacterial infections of the urinary tract. NTP Toxicology and Carcinogenesis studies were conducted by feeding diets containing nalidixic acid (approximately 99% pure) to groups of F344/N rats and B6C3F1 mice of each sex for 13 weeks or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, mouse lymphoma cells, and Chinese hamster ovary (CHO) cells. Thirteen-Week Studies: Nalidixic acid was administered at dietary concentrations ranging from 1,000 to 16,000 ppm. One female rat that received 16,000 ppm nalidixic acid died before the end of the studies; no other compound-related deaths occurred in rats and mice. The final mean body weights of rats that received 8,000 or 16,000 ppm were 23% or 49% lower than those of controls for males and 11% or 31% lower for females. Feed consumption by rats receiving 16,000 ppm was approximately two-thirds that by controls. Liver weight to body weight ratios for male rats that received 2,000 ppm or more and female rats that received 8,000 ppm or more were significantly greater than those for controls. Degeneration of the germinal epithelium in the seminiferous tubules of the testis was observed in 10/10 male rats that received 16,000 ppm; no other compound-related histopathologic effects were observed in rats. The final mean body weights of mice that received 8,000 or 16,000 ppm were 10%-20% lower than those of controls. Feed consumption by dosed mice was similar to that by controls. Liver weight to body weight ratios were significantly greater for male mice receiving 2,000, 8,000, or 16,000 ppm and for female mice receiving 4,000, 8,000, or 16,000 ppm than for the controls. No compound-related histopathologic effects were observed in mice. Based on these results, 2-year studies of nalidixic acid were conducted by feeding diets containing 0, 2,000, or 4,000 ppm nalidixic acid to groups of 50 male and 50 female F344/N rats and 50 male and 50 female B6C3F1 mice. Body Weight and Survival in the Two-Year Studies: Mean body weights of high dose rats were 7%-23% lower than those of controls, and those of low dose male rats were 6%-11% lower than those of controls. The average daily feed consumption by dosed rats ranged from 89% to 96% that by controls. The average amount of nalidixic acid consumed per day was approximately 80 or 175 mg/kg for low dose or high dose rats. Mean body weights of high dose male mice were 1%-8% lower than those of controls throughout the study. Mean body weights of dosed female mice were 5%-17% lower than those of controls. Average daily feed consumption by dosed mice was within 3% of that by controls. The estimated average amount of nalidixic acid consumed per day was approximately 220 or 475 mg/kg for low dose or high dose mice. No significant differences in survival were seen between any groups of rats or mice of either sex after 2 years (male rats: control, 27/50; low dose, 28/50; high dose, 27/50; female rats: 22/50; 31/50; 29/50; male mice: 33/50; 34/50; 31/50; female mice: 40/50; 43/50; 32/50). Nonneoplastic and Neoplastic Effects in the Two-Year Studies: The incidences of preputial gland neoplasms in dosed male rats and of clitoral gland neoplasms in dosed female rats were significantly greater than those in controls (male--preputial gland adenomas, papillomas, or carcinomas, combined: control, 3/49; low dose, 19/49; high dose, 20/47; female--clitoral gland adenomas, papillomas, or carcinomas, combined: 5/46; 15/46; 16/47). A squamous cell carcinoma of the tongue was seen in two high dose male rats. The historical incidence of oral cavity neoplasms in untreated control male F344/N rats is 7/1,596 (0.4%). There were decreased incidences of leukemia (20/50; 9/50; 7/50) and mammary gland neoplasms (10/50; 7/50; 2/50) in dosed female rats and of pituitary gland neoplasms (11/49; 2/50; 2/50) in dosed male rats. Retinal degeneration and cataracts of the eye were observed at increased incidences in dosed rats (degeneration--male: 4/48; 41/48; 47/49; female: 2/47; 40/48; 46/50; cataracts--malee observed at increased incidences in dosed rats (degeneration--male: 4/48; 41/48; 47/49; female: 2/47; 40/48; 46/50; cataracts--male: 11/48; 23/48; 38/49; female: 0/47; 18/48; 14/50). The cause of these cataracts and retinal degeneration is uncertain because cages were not rotated and low and high dose groups of rats may have been exposed to greater light intensity than were the controls. Subcutanous tissue fibrosarcomas and fibromas or fibrosarcomas (combined) were increased in dosed male mice (fibromas or fibrosarcomas, combined: 5/50; 9/50; 14/50). There were no increased incidences of neoplasms in dosed female mice. Genetic Toxicology: Nalidixic acid was not mutagenic in any of several in vitro short-term tests. No gene reversion was observed in S. typhimurium strains TA97, TA98, TA100, or TA1535 after exposure to nalidixic acid in either the presence or absence of exogenous metabolic activation. Results of tests for induction of trifluorothymidine resistance in mouse L5178Y/TK lymphoma cells were negative with or without metabolic activation. In CHO cells, nalidixic acid did not induce sister chromatid exchanges or chromosomal aberrations in either the presence or absence of activation. Conclusions: Under the conditions of these 2-year feed studies, there was clear evidence of carcinogenic activity of nalidixic acid for F344/N rats, as indicated by increased incidences of preputial gland neoplasms in males and clitoral gland neoplasms in females. There was equivocal evidence of carcinogenic activity for male B6C3F1 mice fed diets containing nalidixic acid, as indicated by marginally increased incidences of subcutaneous tissue neoplasms. There was no evidence of carcinogenic activity for female B6C3F1 mice fed diets containing 2,000 or 4,000 ppm nalidixic acid for 2 years. Synonym: 1-ethyl-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylic acid Trade Names: NegGram&reg;.; Dixiben&reg;.; Nalidixan&reg;.; Nalurin&reg;.; Nogram&reg;.; UroNeg&reg;.; Uralgin&reg;.; Urisal&reg;.

Journal Article↗
PubMed1990

NTP Toxicology and Carcinogenesis Studies of Phenylbutazone (CAS No. 50-33-9) in F344/N Rats and B6C3F1 Mice (Gavage Studies).

Phenylbutazone is a nonsteroidal anti-inflammatory drug. NTP Toxicology and Carcinogenesis studies were conducted by administering phenylbutazone (greater than 99% pure) in corn oil by gavage to groups of F344/N rats and B6C3F1 mice of each sex for 19 days, 13 weeks, or 2 years. Genetic toxicology studies were performed with Salmonella typhimurium, mouse L5178Y lymphoma cells, and Chinese hamster ovary (CHO) cells. Nineteen-Day Studies: The deaths of 3/5 male and 4/5 female rats that received 600 mg/kg and of 2/5 females that received 300 mg/kg were considered to be chemically related. The final mean body weight of rats that received 300 or 600 mg/kg was 14%-15% or 46% lower than that of vehicle controls. No compound-related deaths occurred in mice (doses up to 600 mg/kg). The final mean body weights of dosed and vehicle control mice were similar. Thirteen-Week Studies: Most rats that received 300 mg/kg and 1/10 male and 2/10 female rats that received 200 mg/kg died early. The final mean body weight of male rats at 300 mg/kg was 31% lower than that of the vehicle controls. The liver weight to body weight ratios were increased in the 200 and 300 mg/kg group of rats. Compound-related lesions occurred mainly in the kidney and included papillary necrosis, papillary edema, and multifocal mineralization. Five of 10 male mice and 4/10 female mice that received 600 mg/kg died early. No other compound-related deaths occurred in mice. Final mean body weights of dosed and vehicle control mice were comparable. The liver weight to body weight ratios were increased for mice at 300 and 600 mg/kg. No compound-related histopathologic effects were observed in mice. Body Weight and Survival in the Two-Year Studies: Two-year studies were conducted by administering 0, 50, or 100 mg/kg phenylbutazone in corn oil by gavage to groups of 50 rats of each sex, 5 days per week for 103 weeks. The doses given groups of 50 mice of each sex on the same schedule were 0, 150, or 300 mg/kg. Mean body weights of high dose rats were generally 6%-11% lower than those of vehicle controls. Mean body weights of mice were similar among all groups except for high dose female mice, which weighed 4%-11% less than vehicle controls. The survival of all groups was similar except for that of the low dose group of male rats, which was significantly lower than that of the vehicle controls at the end of the studies; the survival of the top dose group of female rats and the vehicle control group of female mice was low but not statistically reduced(final survival--male rats: vehicle control, 33/50; low dose, 20/50; high dose, 27/50; female rats: 31/50; 35/50; 22/50; male mice: 36/50; 40/50; female mice: 22/50; 29/50; 32/50). Nonneoplastic and Neoplastic Effects in the Two-Year Studies: Mild pyelonephritis, renal papillary necrosis, and mineralization of the renal papillae in dosed male and female rats and hyperplasia of the renal pelvis epithelium, dilatation of the renal pelvis, and renal cysts in dosed female rats were observed at increased incidences compared with those in vehicle controls. A renal tubular cell carcinoma was observed in one low dose male rat, and renal tubular adenomas were observed in three high dose male rats. A carcinoma of uncertain histogenesis was observed in one low dose female rat. Carcinomas of the renal transitional epithelium were seen in two high dose female rats. When the kidneys were step-sectioned, additional tubular cell adenomas were diagnosed in four low dose and one high dose male rats and in three low dose and one high dose female rats; none was observed in vehicle controls. Papillomas of the transitional epithelium of the urinary bladder were seen in 2/43 low dose male and 1/49 low dose female F344/N rats. The historical incidence of urinary bladder transitional cell neoplasms in male corn oil vehicle control F344/N rats is 5/2,034 (0.2%; highest observed incidence, 2/50) and 4/2,026 (0.2%; highest observed incidence, 1/45) in females. Adrenal medullary hyperplasia was observed at an increased incidence in high dose female rats (veherplasia was observed at an increased incidence in high dose female rats (vehicle control, 3/50; low dose, 6/50; high dose, 19/50). Ulcers of the forestomach were observed at increased incidences in high dose rats (male: 0/50; 5/50; 6/50; female: 2/49; 1/49; 12/49). In high dose female rats, acanthosis (4/49; 0/49; 12/49), hyperkeratosis (3/49; 0/49; 12/49), and basal cell hyperplasia (4/49; 1/49; 12/49) of the forestomach were observed at increased incidences. No neoplasms were associated with these stomach lesions. Peliosis hepatis, centrilobular cytomegaly and karyomegaly, fatty change, hepatocellular degeneration, and coagulative necrosis of the liver were observed in dosed male mice; clear cell foci were observed in five high dose male mice. The incidences of hepatocellular adenomas and adenomas or carcinomas (combined) in male mice were increased in the high dose group (adenomas or carcinomas, combined: 16/50; 14/50; 31/50). Genetic Toxicology: Phenylbutazone was not mutagenic in S. typhimurium strains TA98, TA100, TA1535, or TA1537 when tested with or without exogenous metabolic activation. Phenylbutazone produced a positive response in the mouse lymphoma assay in both the presence and absence of activation. Phenylbutazone induced chromosomal aberrations in CHO cells in the presence, but not the absence, of exogenous metabolic activation; no induction of sister chromatid exchanges was observed in CHO cells in the presence or absence of activation. Conclusions: Under the conditions of these 2-year gavage studies, there was equivocal evidence of carcinogenic activity of phenylbutazone for male F344/N rats, as shown by the occurrence of small numbers of renal tubular cell adenomas or carcinomas. There was some evidence of carcinogenic activity for female F344/N rats, as shown primarily by the occurrence of two rare transitional cell carcinomas in the top dose group; none has ever been seen in vehicle control or untreated control female rats. Tubular cell adenomas may have been associated with the administration of phenylbutazone to female rats. There was some evidence of carcinogenic activity for male B6C3F1 mice, as shown by the increased incidence of hepatocellular adenomas or carcinomas (combined). There was no evidence of carcinogenicity for female B6C3F1 mice administered phenylbutazone in corn oil by gavage at doses of 150 or 300 mg/kg. Phenylbutazone was also nephrotoxic to rats, as shown by the dose-related increase in the severity of age-related nephropathy, necrosis of the renal papilla, and mineralization of the collecting ducts in the papilla. Synonyms: 4-butyl-1,2-diphenyl-3,5-pyrazolidinedione; 3,5-dioxo-1,2-diphenyl-4-n-butylpyrazolidine Trade Names: There have been over 100 registered trade names including: Anerval; Azobutil; Bizolin 200; Butacote; Butadion; Butagesic; Butazolidin; Chembutazone; Equi Bute; Flexazone; Fenibutol; G 13,871; Pyrazolidin; Reumazol; Robizon-V; Uzone

Journal Article↗
PubMed1989

NTP Toxicology and Carcinogenesis Studies of Hydroquinone (CAS No. 123-31-9) in F344/N Rats and B6C3F1 Mice (Gavage Studies).

Hydroquinone is used an antioxidant in the rubber industry and as a developing agent in photography. It is also an intermediate in the manufacture of rubber and food antioxidants and monomer inhibitors. Hydroquinone and products containing hydroquinone are used as depigmenting agents to lighten skin. NTP Toxicology and Carcinogenesis studies were conducted by administering hydroquinone (greater than 99% pure) in corn oil or water by gavage to groups of F344/N rats and B6C3F1 mice of each sex for 14 days, 13 weeks, or 2 years. Additionally, genetic toxicology studies were conducted in Salmonella typhimurium, mouse lymphoma cells, Chinese hamster ovary (CHO) cells, and Drosophila melanogaster. Preliminary 3-day dermal studies were conducted with rats and mice using sufficient hydroquinone in 95% ethanol to crystallize on the skin (4 or 40 mg per animal); conjugated metabolites of hydroquinone were detected in the urine. Fourteen-day dermal studies were conducted at doses up to 3,840 mg/kg for rats and 4,800 mg/kg for mice. No toxic effects were seen in the 3- or 14-day dermal studies. Therefore, in further evaluations of hydroquinone, the gavage route of administration was used. Results of Fourteen-Day and Thirteen-Week Studies: Fourteen-day gavage studies were conducted by administering hydroquinone in corn oil to rats at doses ranging from 63 to 1,000 mg/kg body weight and to mice at doses ranging from 31 to 500 mg/kg. All rats receiving 1,000 mg/kg and 1/5 male and 4/5 female rats receiving 500 mg/kg died before the end of the 14 days. Compound-related clinical signs in rats included tremors lasting up to 30 minutes after each dosing at 500 and 1,000 mg/kg. In the 14-day gavage studies with mice, 4/5 male mice and 5/5 female mice receiving 500 mg/kg and 3/5 males receiving 250 mg/kg died before the end of the studies. Tremors followed by convulsions were seen at 250 and 500 mg/kg. In the 13-week studies, doses for rats and mice ranged from 25 to 400 mg/kg. All rats receiving 400 mg/kg and 3/10 female rats receiving 200 mg/kg died before the end of the studies. The mean body weight at necropsy of male rats administered 100 or 200 mg/kg was about 8%-9% lower than that of vehicle controls. Mean body weights of vehicle control and dosed female rats at necropsy were similar. Tremors and convulsions were observed after dosing in most rats receiving 400 mg/kg and in several female rats receiving 200 mg/kg. Inflammation and/or epithelial hyperplasia (acanthosis) of the forestomach were seen in 4/10 male rats and 1/10 female rats receiving 200 mg/kg. Toxic nephropathy, characterized by tubular cell degeneration in the renal cortex, was seen in 7/10 male and 6/10 female rats receiving 200 mg/kg and in 1/10 females receiving 100 mg/kg. In the 13-week studies in mice, 8/10 males and 8/10 females receiving 400 mg/kg and 2/10 male mice receiving 200 mg/kg died early. Mean body weights of dosed and vehicle control mice at necropsy were similar. Liver weight to body weight ratios for dosed male mice were significantly greater than for vehicle controls. Ulceration, inflammation, or epithelial hyperplasia of the forestomach was found in 3/10 male and 2/10 female mice receiving 400 mg/kg and 1/10 females receiving 200 mg/kg. Based on these collective results, 2-year studies were conducted by administering 0, 25, or 50 mg/kg hydroquinone in deionized water by gavage to groups of 65 rats of each sex, 5 days per week. Groups of 65 mice of each sex were administered 0, 50, or 100 mg/kg on the same schedule. Ten rats and 10 mice from each group were killed after 15 months for an interim evaluation. Observations at Fifteen Months: In the rats killed at 15 months, the relative kidney weight for high dose male rats was greater than that for vehicle controls. The hematocrit value, hemoglobin concentration, and erythrocyte count for high dose female rats were decreased. Compound-related increased severity of nephropathy was observed in male rats. In mice killed at 15 months, the relative liver weights for high dose male and female mice were signif and female mice were significantly greater than those for vehicle controls. Lesions seen in the liver of male mice included increased syncytial cells and diffuse cytomegaly. Body Weights, Organ Weights, and Survival in the Two-Year Studies: Mean body weights of high dose male rats were 5&percnt;-13&percnt; lower than those of vehicle controls after week 73, and those of low dose male rats were 5&percnt;-9&percnt; lower than those of vehicle controls after week 89. Mean body weights of dosed female rats were similar to those of vehicle controls throughout the study. The relative kidney and liver weights for high dose male rats were higher than those for vehicle controls. Mean body weights of high dose male mice were 5&percnt;-8&percnt; lower than those of vehicle controls after week 93, and those of high dose female mice were 5&percnt;-14&percnt; lower after week 20. Relative liver weights were increased for dosed male and high dose female mice. No significant differences in survival were observed between any groups of rats or mice of either sex after 2 years (male rats: vehicle control, 27/55; low dose, 18/55; high dose, 18/55; female rats: 40/55; 27/55; 32/55; male mice: 33/55; 37/54; 36/55; female mice: 37/55; 39/55; 36/55). Nonneoplastic and Neoplastic Effects in the Two-Year Studies: Nearly all male rats and most female rats in all vehicle control and dosed groups had nephropathy. The severity of this disease was judged to be greater in high dose male rats. Hyperplasia of the renal pelvic transitional epithelium and renal cortical cysts, changes observed with advanced renal disease, were increased in male rats. Renal tubular hyperplasia was seen in 2 high dose male rats, and renal tubular adenomas were seen in 4/55 low dose and 8/55 high dose male rats; none was seen in vehicle controls. Mononuclear cell leukemia in female rats occurred with a positive trend, and the incidences in the dosed groups were greater than that in the vehicle controls (vehicle control, 9/55; low dose, 15/55; high dose, 22/55). The historical incidence of leukemia in water gavage vehicle control female F344/N rats is 25&percnt; &plusmn; 15&percnt; and in untreated controls is 19&percnt; &plusmn; 7&percnt;. Compound-related lesions observed in the liver of high dose male mice included anisokaryosis (0/55; 2/54; 12/55), syncytial alteration (5/55; 3/54; 25/55), and basophilic foci (2/55; 5/54; 11/55). The incidences of hepatocellular adenomas were increased in dosed male mice (9/55; 21/54; 20/55), but these increases were offset by decreases in the incidences of hepatocellular carcinomas (13/55; 11/54; 7/55). The incidences of hepatocellular neoplasms, primarily adenomas, were increased in dosed female mice (3/55; 16/55; 13/55). Follicular cell hyperplasia of the thyroid gland was increased in dosed mice (male: 5/55; 15/53; 19/54; female: 13/55; 47/55; 45/55). Follicular cell adenomas were seen in 2/55 vehicle control, 1/53 low dose, and 2/54 high dose male mice and in 3/55 vehicle control, 5/55 low dose, and 6/55 high dose female mice, a follicular cell carcinoma was seen in a seventh high dose female mouse. The highest observed incidence of follicular cell adenomas or carcinomas(combined) in historical water gavage vehicle control female B6C3F1 mice is 3/48 (6&percnt;). Genetic Toxicology: Hydroquinone was not mutagenic in S. typhimurium strains TA98, TA100, TA1535, or TA1537 with or without exogenous metabolic activation. It induced trifluorothymidine (Tft) resistance in mouse L5178Y/TK lymphoma cells in the presence or absence of metabolic activation. An equivocal response was obtained in tests for induction of sex-linked recessive lethal mutations in Drosophila administered hydroquinone by feeding. Hydroquinone induced sister chromatid exchanges (SCEs) in CHO cells both with or without exogenous metabolic activation and caused chromosomal aberrations in the presence of activation. Conclusions: Under the conditions of these 2-year gavage studies, there was some evidence of carcinogenic activity of hydroquinone for male F344/N rats, as shown by marked increases in tubular cell adenomas of the kidney. There was some evidence of carcinogenic activity of hydroquinone for female F344/N rats, as shown by increases in mononuclear cell leukemia. There was no evidence of carcinogenic activity of hydroquinone for male B6C3F1 mice administered 50 or 100 mg/kg in water by gavage. There was some evidence of carcinogenic activity of hydroquinone for female B6C3F1 mice, as shown by increases in hepatocellular neoplasms, mainly adenomas. Administration of hydroquinone was associated with thyroid follicular cell hyperplasia in both male and female mice and anisokaryosis, multinucleated hepatocytes, and basophilic foci of the liver in male mice. Synonyms: 1,4-benzenediol; p-benzenediol; benzohydroquinone; benzoquinol; 1,4-dihydroxybenzene; p-dihydroxybenzene; p-dioxobenzene; p-dioxybenzene; hydroquinol; hydroquinole; a-hydroquinone; p-hydroquinone; p-hydroxyphenol; quinol; b-quinol

Journal Article↗
PubMed1989

NTP Toxicology and Carcinogenesis Studies of Pentaerythritol Tetranitrate (CAS No. 78-11-5) with 80% D-Lactose Monohydrate (PETN, NF) in F344/N Rats and B6C3F1 Mice (Feed Studies).

Pentaerythritol tetranitrate (PETN, NF) is a drug used to prevent angina pectoris. PETN without a lactose stabilizer is used as an explosive. NTP Toxicology and Carcinogenesis studies were conducted by administering PETN, NF, to groups of F344/N rats and B6C3F1 mice of each sex once by gavage or in feed for 14 days, 13 or 14 weeks, or 2 years. The PETN component was greater than 99% pure. Genetic toxicology studies were conducted with Salmonella typhimurium and Chinese hamster ovary (CHO) cells. Fourteen-Day and Thirteen-Week Studies: All rats and mice lived to the end of the 14-day studies (dietary concentrations up to 50,000 ppm). Final mean body weights of dosed and control rats were comparable. The final mean body weight of female mice that received 50,000 ppm was 13% lower than that of controls. No clinical signs or toxic lesions were attributed to PETN, NF, administration. All rats and mice lived to the end of the 13-week (mice) and 14-week (rats) studies (dietary concentrations up to 50,000 ppm). Final mean body weights of dosed and control rats and mice were similar, although weight gains of female rats at 25,000 and 50,000 ppm were less than that of controls. The nitrite level in urine of rats and methemoglobin levels in whole blood of rats and mice were not affected by administration of PETN, NF. An adenoma of the Zymbal gland was seen in a female rat that received 50,000 ppm. A hepatocellular adenoma was seen in a female mouse that received 50,000 ppm. Based on these results and the NTP convention of limiting concentrations in 2-year feed studies to 5% of the diet, the 2-year studies were conducted by administering 0, 25,000 or 50,000 ppm PETN, NF, in feed for 104 weeks to groups of 50 male rats and for 103 weeks to groups of 49 or 50 mice of each sex. Groups of 50 female rats were given feed containing 0, 6,200, or 12,500 ppm PETN, NF, for 104 weeks. Body Weight and Survival in the Two-Year Studies: Mean body weights of high dose male rats were 2%-9% lower than those of controls throughout the study; body weights of all groups of female rats were similar. No significant differences in survival were observed between any groups of rats of either sex (male: control, 23/50; low dose, 29/50; high dose, 29/50; female: 33/50; 33/50; 31/50). Mean body weights of dosed and control mice were similar. The survival of both groups of dosed male mice was significantly greater than that of the controls (26/49; 38/50; 38/50). No significant differences in survival were observed between any groups of female mice (38/50; 30/50; 38/50). Nonneoplastic and Neoplastic Effects in the Two-Year Studies: No nonneoplastic lesions were attributed to PETN, NF, administration in rats or mice. Neoplasms of the Zymbal gland occurred in dosed male (control, 0/49; low dose, 3/45; high dose, 2/41) and dosed female (0/36; 1/37; 3/35) rats. The historical incidence of these neoplasms is 1% +/- 2% in untreated males and 0.6% +/- 1% in females. At no site was a significantly increased incidence of neoplasms observed in dosed male or female mice. Genetic Toxicology: PETN, NF, was not mutagenic in S. typhimurium strains TA98, TA100, TA1535, or TA1537 when tested with or without exogenous metabolic activation (S9). When tested for cytogenetic effects in cultured CHO cells, PETN, NF, induced sister chromatid exchanges (SCEs) in the presence and absence of metabolic activation; no induction of chromosomal aberrations was observed in CHO cells with or without activation. Audit: The data, documents, and pathology materials from the 2-year studies of PETN, NF, have been audited. The audit findings show that the conduct of the studies is documented adequately and support the data and results given in this Technical Report. Conclusions: Under the conditions of these 2-year feed studies, there was equivocal evidence of carcinogenic activity of PETN, NF, for male and female F344/N rats, based on a marginal increase in neoplasms of the Zymbal gland. Female rats might have tolerated a higher dose. There was no evidence of carcinogenic activity of PETN, NF, forher dose. There was no evidence of carcinogenic activity of PETN, NF, for male or female B6C3F1 mice fed diets containing 25,000, or 50,000 ppm for 2 years. No nonneoplastic lesions were attributed to PETN, NF, administration. Synonyms for PETN: 2,2-bis((nitrooxy)methyl)-1,3-propanediol dinitrate (ester); 2,2-bisdihydroxy-methyl-1,3-propanediol tetranitrate; niperyt; nitropentaerythritol; pentaerythrityl tetranitrate; penthrit Trade Names for PETN, NF: Angitet; Cardiacap; Dilcoran-80; Dipentrate; Hasethrol; Lentrat; Metranil; Mycardol; Neo-Corovas; Nitropenta; Nitropenton; Pentafin; Pentanitrine; Pentitrate; Pentral 80; Pentrite; Pentritol; Pentryate; Peridex; Pergitral; Peritrate; Perityl; Prevangor; Quintrate; Subicard; Terpate; Vasodiatol

Journal Article↗
PubMed1989

NTP Toxicology and Carcinogenesis Studies of Rhodamine 6G (C.I. Basic Red 1) (CAS No. 989-38-8) in F344/N Rats and B6C3F1 Mice (Feed Studies).

NTP Toxicology and Carcinogenesis studies of rhodamine 6G were conducted because of potential human exposure related to its use as a dye for natural and synthetic fibers and as a research chemical. These studies were conducted by administering rhodamine 6G (greater than 95% pure) in feed to groups of F344/N rats and B6C3F1 mice of each sex for 14 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, mouse L5178Y lymphoma cells, and Chinese hamster ovary (CHO) cells. Fourteen-Day and Thirteen-Week Studies: In the 14-day studies (0, 310, 620, 1,250, 2,500, or 5,000 ppm), all five male and five female rats that received 5,000 ppm and 1/5 male rats that received 2,500 ppm died before the end of the studies; all mice lived to the end of the study. The final mean body weights of rats that received 2,500 ppm were lower than the initial weights. The final mean body weights of mice that received 2,500 or 5,000 ppm were 8% or 18% lower than that of controls for males and 2% or 8% lower for females. In the 13-week studies, all rats lived to the end of the studies (dietary concentrations of 0 or 120-2,000 ppm). The final mean body weights of rats that received 500, 1,000 or 2,000 ppm were 12%, 13%, or 32% lower than that of controls for males and 4%, 8%, or 20% lower for females. Feed consumption by rats that received 2,000 ppm was somewhat lower than that by controls. Bone marrow atrophy was observed at increased incidences and severity in dosed rats. In the 13-week study (0 or 500-8,000 ppm), 1/10 male mice that received the highest concentration died before the end of the studies. The final mean body weights of mice that received 8,000 ppm were lower than the initial mean body weights. The final mean body weights of male mice that received 4,000 ppm and of female mice that received 2,000 or 4,000 ppm were 13%-19% lower than those of controls. Feed consumption was not related to dose. Minimal-to-moderate cytoplasmic vacuolization of hepatocytes was seen in 8/10 male mice that received 8,000 ppm. Based on these results, dietary concentrations selected for the 2-year studies were 0, 120, or 250 ppm rhodamine 6G for rats, 0, 1,000, or 2,000 ppm for male mice, and 0, 500, 1,000 ppm for female mice. Body Weight and Survival in the Two-Year Studies: Mean body weights of dosed rats were similar to those of controls throughout the studies. The average daily feed consumption by dosed rats was within 5% that by controls for all dosed groups. The average amount of rhodamine 6G consumed per day was approximately 5 mg/kg for low dose rats and 10 or 12 mg/kg for high dose male or female rats. Mean body weights of high dose male and dosed female mice were generally 5%-14% lower than those of controls. The average daily feed consumption by dosed mice was within 5% that by controls for all dosed groups. The average amount of rhodamine 6G consumed per day was approximately 210 or 440 mg/kg for low dose or high dose male mice and 125 or 250 mg/kg for low dose or high dose female mice. No significant differences in survival were observed between any groups of rats or mice (male rats: control, 22/50; low dose, 21/50; high dose, 27/50; female rats: 29/50; 30/50; 30/50; male mice: 36/50; 32/50; 38/50; female mice: 39/50; 35/50; 36/50). Nonneoplastic and Neoplastic Effects in the Two-Year Studies: No chemically related nonneoplastic lesions in male or female rats and no chemically related neoplastic or nonneoplastic lesions in male or female mice were observed in these studies. The incidences of keratoacanthomas of the skin was increased in high dose male rats (control, 1/50; low dose, 2/50; high dose, 8/50). The historical incidence of keratoacanthomas in untreated control male F344/N rats is 31/1,936 (1.6%; range, 0/50-7/49). Both fur and skin of rats in the dosed groups apparently were exposed to feed dust containing rhodamine 6G; the intensity of staining was proportional to the concentration of rhodamine 6G in feed. Because of the variable background incidence of keratoacanthomas in F344/N rats, the incideentration of rhodamine 6G in feed. Because of the variable background incidence of keratoacanthomas in F344/N rats, the incidence of keratoacanthomas cannot be conclusively related to exposure to rhodamine 6G. The incidences of pheochromocytomas (3/50; 3/50; 8/50) or malignant pheochromocytomas (combined: 3/50; 3/50; 10/50) of the adrenal gland were increased in high dose female rats. The historical incidence of adrenal medullary neoplasms in untreated control F344/N female rats is 99/1,968 (5&percnt;; range, 0/50-8/50). This marginal increase may be related to the administration of rhodamine 6G. Genetic Toxicology: Rhodamine 6G was not mutagenic in S. typhimurium strains TA98, TA100, TA1535, or TA1537 when tested with and without exogenous metabolic activation (S9). Rhodamine 6G gave a positive response in the absence of S9 in the mouse lymphoma assay for induction of trifluorothymidine (Tft) resistance in L5178Y cells; in the presence of S9, rhodamine 6G was negative. Rhodamine 6G induced sister chromatid exchanges (SCEs) and chromosomal aberrations in cultured CHO cells in the presence, but not the absence, of S9. Conclusions: Under the conditions of these 2-year feed studies, there was equivocal evidence of carcinogenic activity for male F344/N rats administered rhodamine 6G, as indicated by a marginally increased incidence of integumentary keratoacanthomas. There was equivocal evidence of carcinogenic activity for female F344/N rats administered rhodamine 6G, as indicated by a marginal increase in pheochromocytomas or malignant pheochromocytomas (combined) of the adrenal gland. There was no evidence of carcinogenic activity for male B6C3F1 mice administered 1,000 or 2,000 ppm rhodamine 6G in the diet. There was no evidence of carcinogenic activity for female B6C3F1 mice administered 500 or 1,000 ppm rhodamine 6G in the diet. There were no significant nonneoplastic lesions attributed to rhodamine 6G administration to male or female rats or male or female mice. Male and female rats might have been able to tolerate a higher concentration of rhodamine 6G in the feed. Synonym: 2-[6-(ethylamino)-3-(ethylimino)2,7-dimethyl-3H-xanthen-9-yl] benzoic acid ethyl ester, monohydrochloride Common Names: Basic Red 1; Basic Rhodamine Yellow; Basic Rhodaminic Yellow; Calcozine Red 6G; Calcozine Rhodamine 6GX; C.I. Basic Red 1, Monohydrochloride; Elcozine Rhodamine 6GDN; Eljon Pink Toner; Fanal Pink GFK; Fanal Red 25532; Flexo Red 482; Heliostable Brilliant Pink B extra; Mitsui Rhodamine 6GCP; Nyco Liquid Red GF; Rhodamine 69DN Extra; Rhodamine F4G; Rhodamine F5G; Rhodamine F5G chloride; Rhodamine 6GB; Rhodamine 6GBN; Rhodamine 6GCP; Rhodamine 6GD; Rhodamine 4GD; Rhodamine GDN; Rhodamine 5GDN; Rhodamine 6 GDN; Rhodamine GDN Extra; Rhodamine 6GEx ethyl ester; Rhodamine 6G Extra; Rhodamine 6G Extra Base; Rhodamine 4GH; Rhodamine 6GH; Rhodamine 5GL; Rhodamine 6G lake; Rhodamine 6GX; Rhodamine J; Rhodamine 6JH; Rhodamine 7JH; Rhodamine Lake Red 6G; Rhodamine Y 20-7425; Rhodamine Zh; Rhodamine 6ZH-DN; Silosuper Pink B; Valley Fast Red 1308

Journal Article↗
PubMed1990

NTP Toxicology and Carcinogenesis Studies of l-Epinephrine Hydrochloride (CAS No. 55-31-2) in F344/N Rats and B6C3F1 Mice (Inhalation Studies).

l-Epinephrine, an endogenous neurotransmitter hormone, is widely used for the treatment of allergic and respiratory disorders. NTP Toxicology and Carcinogenesis studies of epinephrine hydrochloride were conducted by exposing groups of F344/N rats and B6C3F1 mice of each sex to an aerosol containing epinephrine hydrochloride for 14 days, 13 weeks, 15 months, or 2 years. During the 14-day and 13-week studies, control animals were exposed to dilute aerosols of hydrochloric acid (pH 2.8), whereas during the 15-month and 2-year studies, controls were exposed to aerosols of water. Genetic toxicology studies of epinephrine were conducted in Salmonella typhimurium and Chinese hamster ovary (CHO) cells. Fourteen-Day Studies: Rats and mice were exposed to 0 or 12.5-200 mg/m3 epinephrine hydrochloride. Deaths occurred in male rats exposed to 12.5 mg/m3 or more and in females exposed to 25 mg/m3 or more. Deaths of mice occurred at concentrations of 50 mg/m3 or higher. Compound-related clinical signs included an increased respiratory rate in all groups of epinephrine-exposed rats and mice. At higher concentrations (100 and 200 mg/m3), excessive lacrimation and dyspnea in rats and exaggerated visual and auditory reflexes in mice were observed. Thirteen-Week Studies: Rats and mice were exposed to 0 or 2.5-40 mg/m3 epinephrine hydrochloride. Deaths in rats and mice were not concentration related. Final mean body weights of chemically exposed and hydrochloric acid aerosol control rats and mice were generally similar. Increased respiratory rates were noted in rats and mice exposed to 40 mg/m3. Heart and adrenal gland weights of rats and mice and liver weights of mice exposed to 40 mg/m3 were greater than those of aerosol controls. Squamous metaplasia occurred in the respiratory epithelium of the nasal mucosa of rats and mice exposed to 40 mg/m3. Degenerative lesions of the laryngeal muscle were seen in male and female rats exposed to 20 or 40 mg/m3. Inflammation in the glandular stomach was seen in male and female mice exposed to 10, 20, and 40 mg/m3, and uterine atrophy was seen in 7/10 female mice exposed to 40 mg/m3. Two-year studies were conducted by exposing groups of 60 rats or each sex to 0, 1.5, or 5 mg/m3 epinephrine hydrochloride, 5 days per week for 103 weeks. Groups of 60 mice of each sex were exposed to 0, 1.5, or 3 mg/m3 epinephrine hydrochloride, 5 days per week for 104 weeks. Use of these exposure concentrations represented a departure from the usual practice of utilizing doses equivalent to one-half the maximum tolerated dose (MTD) and the MTD for 2-year carcinogenicity studies. Thus, although the dose levels exceeded maximum human therapeutic use levels (normalized to body weight and surface area), they were less than one-half the MTD. Fifteen-Month Studies: Results of hematologic analyses did not show compound-related changes. Absolute liver weights for exposed mice (3 mg/m3) and rats (5 mg/m3) and relative liver weights for exposed rats (5 mg/m3) were significantly lower than those for controls. The absolute kidney weights for mice exposed to 3 mg/m3 and the kidney weight to body weight ratio for male mice exposed to 3 mg/m3 were significantly lower than those for controls. No compound-related lesions were seen in rats or mice. Body Weights and Survival in the Two-Year Studies: Mean body weights and survival of exposed and control rats and mice were similar (survival, rats--male: control, 33/50; 1.5 mg/m3, 27/50; 5 mg/m3, 32/50; female: 32/50; 29/50; 30/50; mice--male: control, 33/50; 1.5 mg/m3, 34/50; 3 mg/m3, 36/50; female: 32/50; 35/50; 34/50). Nonneoplastic and Neoplastic Effects in the Two-Year Studies: Suppurative inflammation of the nasal mucosa, dilatation of the nasal glands (Bowman's and septal), and hyperplasia of the respiratory epithelium were seen at increased incidences in male rats exposed to 5 mg/m3 and in female rats exposed to 1.5 or 5 mg/m3. Hyaline degeneration of the olfactory epithelium in male mice and suppurative inflammation of the nasal passage and hyaline degeneration of the respiratory epithelium in female mice were increased in the 1.5 and 3 mg/m3 groups compared with controls. No neoplasms seen in these studies were considered related to chemical exposure. Genetic Toxicology: Salmonella gene mutation tests with l-epinephrine yielded negative results in strain TA100 in the presence of exogenous metabolic activation (S9) and equivocal results in the absence of S9. No mutagenic activity was observed in strains TA98, TA1535, or TA1537 with or without S9. The responses observed in the CHO cell assay for induction of sister chromatid exchanges were considered to be negative and equivocal in the presence and absence of S9 activation, respectively. l-Epinephrine did not induce chromosomal aberrations in CHO cells with or without S9. Conclusions: Under the conditions of these 2-year studies, no carcinogenic effects were observed in male or female F344/N rats exposed to aerosols containing 1.5 or 5 mg/m3 l-epinephrine hydrochloride for 2 years or in B6C3F1 mice exposed to 1.5 or 3 mg/m3 l-epinephrine hydrochloride for 2 years. However, these studies were considered to be inadequate studies of carcinogenic activity because the concentrations used, which were chosen to represent multiples of therapeutic doses, were considered too low for the animals to have received an adequate systemic challenge from the compound. Synonyms: adrenaline hydrochloride; 4-(1-hydroxy-2-(methylamino)ethyl)-1,2-benzenediol; (-)3,4-dihydroxy-a-((methylamino)methyl)benzyl alcohol hydrochloride; methylaminoethanol catechol hydrochloride Trade names for epinephrine formulations: Primatene&reg;. Mist; Sus-Phrine&reg;.; Epipen&reg;.; Supravenin Hydrochloride&reg;.; Bronkaid&reg;.

Journal Article↗