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At least 19 recordsLinked to original sources
PubMed1993

Developmental toxicity, reproductive toxicity, and neurotoxicity as regulatory endpoints.

For decades, cancer has been the primary toxicological endpoint used in the assessment of hazard and risk. Regulatory decisions related to the manufacture, transport, and use of a chemical are often based solely on cancer data. Federal policy is now shifting toward more frequent evaluation and application of alternative endpoints of toxicity. Among the endpoints of particular current interest are developmental toxicity, reproductive toxicity, and neurotoxicity. Significant progress has been made in the development of standardized guidelines for testing chemicals for their potential effects on these endpoints. Corresponding guidelines for the assessment of risk on the basis of data on these endpoints are in various stages of development.

Embryonic and Fetal Development↗
PubMed1995

Potential parameters of male reproductive toxicity: reproductive performance, histopathology and sperm evaluation in SD rats given nitrazepam.

The present study was designed to elucidate the correlation between findings from reproductive performance testing and those from histopathological examination of the testis and sperm analysis in rats given a benzodiazepine derivative, nitrazepam, for 2 and 4 weeks. The mechanisms of toxicological action of nitrazepam on the male reproductive organs were also investigated. Nitrazepam was given orally to Sprague-Dawley male rats (6-week-old) at a daily dose of 80 mg/kg for 2 weeks or at daily doses of 20, 40 or 80 mg/kg for 4 weeks. Treated males were mated to examine reproductive performance with untreated females after each dosing period, and after 4 and 9 week of recovery periods. Necropsy was performed for histopathological examination of the testis and epididymis and for sperm analysis after each dosing period and the final mating trial (total of 11 weeks recovery). In the findings from reproductive performance testing, significant decrease in the fertility index was observed in the 80 mg/kg group even after 2 weeks dosing and thereafter until 4 weeks recovery, though the mating index did not significantly differ from that of controls through the experiment. In the histopathological examination and sperm analysis, testicular signs of toxicity, decrease in number of sperm heads in the testis and increase in number of sperm with abnormal heads in the seminiferous tubules were noted in the 80 mg/kg group after 2 weeks dosing and in the 40 and 80 mg/kg groups after 4 weeks dosing. Concentrations of plasma testosterone and content of testis testosterone in nitrazepam-treated groups were not significantly different from those of controls. Plasma FSH concentration was significantly elevated in the 80 mg/kg group through the experiment, although significant elevation of plasma LH was observed only after 2 weeks dosing. These results indicate that histopathological examination is the most reliable approach to detect male reproductive adverse effects induced by nitrazepam rather than using parameters from mating trials. The four-week-dosing period is appropriate for their detection. Hypospermatogenesis induced by nitrazepam is suggested to be caused by direct action of nitrazepam on germ cells and/or Sertoli cells rather than by indirect action through inhibition of testosterone secretion.

Animals↗
PubMed2005

Protein expression analysis of rat testes induced testicular toxicity with several reproductive toxicants.

The utilization of safety biomarkers to predict the possibility of compound-related toxicity provides several advantages for drug discovery and development, especially at an early stage. The objectives of this study were to investigate the effects of male reproductive toxicants on protein expression profiles in the rat testes and to identify potential biomarker candidates. Four well-known reproductive toxicants, ethylene glycol monomethyl ether (EGME), cyclophosphamide (CP), sulfasalazine (SASP) and 2,5-hexanedione (2,5-HD), were administered to male rats in a single dose, and protein expression profiles were investigated after 24 hr by two-dimensional gel electrophoresis (2DE). Histopathological examination of the testes and serum concentration analysis were also performed. From the results of the comparison of 2D-gels among different doses of a compound and among compounds, 52, 20, 24 and 111 spots were nominated as differentially expressed spots with EGME, CP, SASP and 2,5-HD treatments, respectively. Several spermatogenesis-involved proteins were identified, including glutathione S-transferase (GST), testis-specific heat shock protein 70-2 (HSP70-2), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and phosphatidylethanolamine-binding protein (PEBP). Some of them were altered by more than one compound. In summary, remarkable histopathological findings were observed only in the EGME high-dose group, and most of the protein changes were detected before histopathological changes occurred. Therefore, the proteins identified in this study could potentially serve as biomarkers to evaluate male reproductive toxicity at an early stage of drug discovery and development.

Animals↗
PubMedDate not supplied

Developmental and reproductive toxicity evaluation of toluene vapor in the rat. I. Reproductive toxicity.

The reproductive toxicity of toluene was evaluated in a 2-generation test in which male and female Sprague-Dawley rats, parental (F0) and first generation (F1), were exposed to toluene via whole body inhalation, 6 h/day, 7 days/week for 80 days premating and 15 days of mating at concentrations of 0, 100, 500 and 2000 ppm (0, 375, 1875 and 7500 mg/m(3)). Toluene was administered at 2000 ppm to both sexes, or to females or males only to be mated with untreated partners. Pregnant females at all dose levels were exposed from gestation day (GD) 1-20 and lactation day (LD) 5-21. At LD5, females were removed from their litters for daily exposure and returned when 6 h of exposure was completed. F1 pups selected to produce the F2 generation were treated for 80 days beginning immediately after weaning (LD21) and initially mated at a minimum of 100 days of age. F2 pups were not exposed to toluene by inhalation. Toluene exposure did not induce adverse effects on fertility, reproductive performance, or maternal/pup behaviors during the lactation period in males and females of the parental or first generation, but did inhibit growth in F1 and F2 offspring in the 2000 ppm (both sexes treated) and 2000 ppm (females only treated) groups. Caesarean section of selected 2000 ppm (both sexes treated) dams at GD20 showed reduced fetal body weight and skeletal variations. Exposure to toluene caused decreased pup weights throughout lactation in F1 and F2 2000 ppm (both sexes treated), and 2000 ppm (females only treated) groups. Exposure at 2000 ppm to male parents only did not induce similar weight inhibition in offspring. The toluene offspring NOAEL is 500 ppm in groups in which maternal animals were exposed, and 2000 ppm for male only treated groups.

Abnormalities, Drug-Induced↗
PubMed2005

An analysis of genetic toxicity, reproductive and developmental toxicity, and carcinogenicity data: II. Identification of genotoxicants, reprotoxicants, and carcinogens using in silico methods.

This study examined a novel method to identify carcinogens that employed expanded data sets composed of in silico data pooled with actual experimental genetic toxicity (genetox) and reproductive and developmental toxicity (reprotox) data. We constructed 21 modules using the MC4PC program including 13 of 14 (11 genetox and 3 reprotox) tests that we found correlated with results of rodent carcinogenicity bioassays (rcbioassays) [Matthews, E.J., Kruhlak, N.L., Cimino, M.C., Benz, R.D., Contrera, J.F., 2005b. An analysis of genetic toxicity, reproductive and developmental toxicity, and carcinogenicity data: I. Identification of carcinogens using surrogate endpoints. Regul. Toxicol. Pharmacol.]. Each of the 21 modules was evaluated by cross-validation experiments and those with high specificity (SP) and positive predictivity (PPV) were used to predict activities of the 1442 chemicals tested for carcinogenicity for which actual genetox or reprotox data were missing. The expanded data sets had approximately 70% in silico data pooled with approximately 30% experimental data. Based upon SP and PPV, the expanded data sets showed good correlation with carcinogenicity testing results and had correlation indicator (CI, the average of SP and PPV) values of 75.5-88.7%. Conversely, expanded data sets for 9 non-correlated test endpoints were shown not to correlate with carcinogenicity results (CI values <75%). Results also showed that when Salmonella mutagenic carcinogens were removed from the 12 correlated, expanded data sets, only 7 endpoints showed added value by detecting significantly more additional carcinogens than non-carcinogens.

Animals↗
PubMed1997

Toxicity of ebrotidine on reproduction. Toxicity on fertility and general reproductive performance, embryo-fetal toxicity and peri- and postnatal toxicity.

Reproduction toxicity studies of ebrotidine (N-[(E)-[[2-[[[2-[(diaminomethylene)amino]-4-thiazolyl]methyl] thio]ethyl]amino]methylene]-4-bromo-benzenesulfonamide, CAS 100981-43-9, FI-3542) are presented in this paper. Rats dosed with 50, 200 and 500 mg/kg p.o. of ebrotidine were used for the fertility and peri- and postnatal toxicity studies, and rabbits dosed with 25, 100 and 250 mg/kg and rats dosed with 50, 200 and 500 mg/kg of ebrotidine were used for the embryotoxicity study. The fertility study was designed in accordance with a 2-generation study protocol. The results showed that ebrotidine did not interfere with male and female gametogenesis, fertility, organogenesis, postnatal development and lactation in F0 or F1 animals. Only general or non-specific effects were attributed to treatment, such as a lower weight gain in parents or fetuses in rats, or a somewhat slower bone calcification in rats, which was shown to be recoverable and had no peri- or postnatal repercussions. Neither did the fertility study reveal a possible longer duration of gestation nor did the peri- and postnatal study show a lower weight of the F1 offspring. There was only an increase in rabbit embryonic mortality, probably related to some cases of abortion at the high dose. No potential antiandrogenic effect on the reproductive function has been found. Among the different doses used in both animal species, the maximum toxic effect-free dose was that of 25 mg/kg.

Abnormalities, Drug-Induced↗
PubMed1989

The mechanisms of action of reproductive toxicants.

Successful human reproduction is a complex process which requires normal function of 2 individuals. Reproductive toxicants can impair reproduction by acting in the male, female or both. Reproductive toxicants can produce their adverse effects by several direct and indirect mechanisms. The mechanisms by which reproductive toxicants impair reproduction are reviewed.

Animals↗
PubMed2005

An analysis of genetic toxicity, reproductive and developmental toxicity, and carcinogenicity data: I. Identification of carcinogens using surrogate endpoints.

A retrospective analysis of standard genetic toxicity (genetox) tests, reproductive and developmental toxicity (reprotox) studies, and rodent carcinogenicity bioassays (rcbioassay) was performed to identify the genetox and reprotox endpoints whose results best correlate with rcbioassay observations. A database of 7205 chemicals with genetox (n = 4961), reprotox (n = 2173), and rcbioassay (n = 1442) toxicity data was constructed; 1112 of the chemicals have both genetox and rcbioassay data and 721 chemicals have both reprotox and rcbioassay data. This study differed from previous studies by using conservative weight of evidence criteria to classify chemical carcinogens, data from 63 genetox and reprotox toxicological endpoints, and a new statistical parameter of correlation indicator (CI, the average of specificity and positive predictivity) to identify good surrogate endpoints for predicting carcinogenicity. Among 63 endpoints, results revealed that carcinogenicity was well correlated with certain tests for gene mutation (n = 8), in vivo clastogenicity (n = 2), unscheduled DNA synthesis assay (n = 1), and reprotox (n = 3). The current FDA regulatory battery of four genetox tests used to predict carcinogenicity includes two tests with good correlation (gene mutation in Salmonella and in vivo micronucleus) and two tests with poor correlation (mouse lymphoma gene mutation and in vitro chromosome aberrations) by our criteria.

Animals↗
PubMed1992

Reproduction toxicity of sertaconazole. Segment II (teratology) and Segment III (peri-postnatal toxicity).

The reproduction toxicity of 7-chloro-3-[1-(2,4-dichlorophenyl)-2- (1H-imidazol-1-yl)ethoxy-methyl]benzo[b]thiophene (sertaconazole, FI-7045, CAS 99592-32-2) (50, 100 and 150 mg/kg by oral route) has been investigated by performing two studies: the embryotoxicity or teratology study in rats and rabbits, and the peri-postnatal toxicity study in rats. According to the results obtained from the embryotoxicity studies, there was no maternal toxicity in either of the two species studied. The only embryofoetal abnormalities with statistical and toxicological significance were observed at the dose of 150 mg/kg in the teratology study on rabbits: hepatomegalia, pericardial oedema and peritoneal and hepatic haemorrhages. The results of the peri-postnatal study showed that the only maternal effect relating to the drug was an increase, proportional to the dose, in the weight of the ovaries, which was significant at the dose of 150 mg/kg. With reference to the offspring, only a reduction in the viability index at 150 mg/kg was observed. The non observed effects level (NOEL) for all three studies can be estimated at 100 mg/kg.

Aging↗
PubMed1990

Reproductive toxicity: male and female reproductive systems as targets for chemical injury.

On the basis of current knowledge of reproductive biology and toxicology, it is apparent that chemicals affecting reproduction may elicit their effects at a number of sites in both the male and the female reproductive system. This multiplicity of targets is attributable to the dynamic nature of the reproductive system, in which the hypothalamic-pituitary-gonadal axis is controlled by precise positive and negative feedback mechanisms among its components. Interference by a xenobiotic at any level in either the male or the female reproductive system may ultimately impair hypothalamic or pituitary function. Normal gonadal processes such as spermatogenesis or oogenesis, ejaculation or ovulation, hormone production by Leydig or granulosa cells, and the structure or function of the accessory reproductive structures (e.g., epididymis, fallopian tube) also appear vulnerable to xenobiotics. The reproductive system is a complex one that requires local and circulating hormones for control. This brief review illustrates a system for characterizing the mechanism of action of reproductive toxicants, as well as for defining the sites available for disruption of reproduction. Unfortunately, at present, data addressing the actual vulnerability of reproduction are sorely lacking. However, when experiments have been conducted and combined with epidemiologic data or clinical observation, it has been possible to demonstrate impairment of reproductive processes by xenobiotics. The role of environmental exposure to xenobiotics in the increase in infertility that has been observed remains to be defined.

Environmental Exposure↗
PubMed1997

Reproductive toxicity testing of pharmaceutical compounds to support the inclusion of women in clinical trials.

1. The potential for toxicity to reproduction and the developing fetus is an important concern requiring attention during the development of new medicines. However, there are differences in the opinions of the regulatory authorities in Europe, Japan and the USA regarding the nature and amount of data from reproductive toxicity tests that should be available at the various stages of clinical development. 2. Forty-one companies or their subsidiaries from Europe, Japan and the USA provided data for a questionnaire-based study, carried out in 1994, to ascertain the practices of pharmaceutical companies and their views on an ideal approach to the timing of reproduction and development toxicity studies in relation to clinical investigation. 3. Differences were identified in the stage of drug development at which animal studies were completed, the sequence of completion of specific studies, and the extent of reproduction testing completed to support the inclusion of women in clinical trials. 4. A harmonised, but flexible, guidelines, encompassing the timing of reproductive toxicity studies in relation to clinical trials, would permit better integration between clinical and non-clinical studies in an international drug development programme.

Animals↗
PubMed1992

The European Community classification of chemicals for reproductive toxicity.

The classification and labelling of dangerous substances was first introduced in 1967 in the European Community with Council Directive 67/548/EEC known as the Dangerous Substances Directive. The "6th Amendment" to this directive in 1979 introduced a notification procedure and a requirement for labelling chemicals for toxicity. Three special categories for labelling were for "Carcinogenicity, Mutagenicity and Teratogenicity". The teratogenicity classification was restricted to chemicals inducing "teratogenic" effects in the classical sense of the word ie. producing only gross structural malformations. Discussions by expert advisors to the European Commission over several years has lead to a widening of concern in this area of toxicology and under the forthcoming "7th Amendment" the classification of "Teratology" will be changed to "Toxic to Reproduction". This will include adverse effects on fertility, pre- and postnatal development and lactation and will encompass not only structural but also functional deficits. This will bring about a major change in the testing requirements to allow adequate classification of chemicals for these other aspects of reproductive toxicity.

Animals↗
PubMed1995

The European Community Directive on the classification and labeling of chemicals for reproductive toxicity.

The classification and labeling of dangerous substances was first introduced in 1967 in the European Community with Council Directive 67/548/EEC, known as the Dangerous Substances Directive. The Sixth Amendment to this directive in 1979 introduced a notification procedure for new chemicals and a requirement for labeling chemicals for toxicity. Three special categories for labeling were for carcinogenicity, mutagenicity, and teratogenicity. The teratogenicity classification was restricted to chemicals inducing teratogenic effects in the classical sense of the word, ie, producing only gross structural malformations. Discussions by expert advisors to the European Commission over several years led to a widening of concern in this area of toxicology and, under the recent Seventh Amendment, the classification of "teratology" has been changed to "toxic to reproduction." This includes adverse effects on fertility, pre- and postnatal development, and lactation, and encompasses not only structural but also functional deficits. This will bring about a major change in the testing requirements to allow adequate classification of chemicals for these other aspects of reproductive toxicity.

European Union↗
PubMed2005

Effects of male reproductive toxicants on gene expression in rat testes.

Predictive biomarkers of testicular toxicity are needed for an efficient development of drugs. The purpose of the present study was to obtain further insight into the toxicity mechanisms of various male reproductive toxicants and to detect genomic biomarkers for rapid screening of testicular toxicity. Four reproductive toxicants, 2,5-hexanedione (Sertoli cells toxicant), ethylene glycol monomethyl ether (EGME; spermatocytes toxicant), cyclophosphamide (spermatogonia toxicant) and sulfasalazine, were orally administered to male rats once. Six hours after the single dosing, gene expression in the testes was monitored by cDNA microarray and real-time RT-PCR and the testes were histopathologically examined. No histopathological abnormality was detected except for slight degeneration of spermatocytes in the EGME-treated testes. cDNA microarray analysis revealed differential gene expression profiles, and it was possible based on the profiles to characterize the action of the compounds in the testes. Interestingly, 3 spermatogenesis-related genes -- heat shock protein 70-2, insulin growth factor binding protein 3 and glutathione S transferase pi -- were affected by all the compounds. The above changes of gene expression were detectable within a short period after the dosing prior to the appearance of obvious pathological changes. These data suggest that cDNA microarray is a useful technique for evaluation of primary testicular toxicity. Furthermore, we propose the above 3 spermatogenesis-related genes as potential biomarkers of testicular toxicity.

Administration, Oral↗
PubMed1990

Chronic toxicity, oncogenic potential, and reproductive toxicity of p-nitroaniline in rats.

Dose levels for these studies were selected mainly on the basis of subchronic studies, although consideration was also given to workplace exposure levels and proposed mechanism of tumor formation with structurally similar compounds. For the chronic study, groups of 60 male and 60 female Sprague-Dawley CD (Registered Trademark of Charles River Breeding Laboratories, Portage, MI) rats were given 0, 0.25, 1.5, or 9.0 mg/kg/day paranitroaniline (PNA) by gavage in corn oil for a period of 2 years. Parameters monitored included clinical observations, ophthalmoscopic exams, body weights, food consumption, hematology, clinical chemistry, and urinalysis at regular intervals throughout the study. All gross lesions and over 40 tissues were examined histologically for all control and high-dosage-level animals. Gross lesions, spleens, and livers of low- and mid-dosage groups were also examined histologically. For the reproduction study, groups of 15 male and 30 female rats, designated as F0 generation, were given PNA at the same levels as the chronic study for 14 weeks prior to mating and during mating, gestation, and lactation. Selected groups of 15 male and 30 female rats of the F1 generation received the same dose of PNA for 18 weeks prior to mating and during mating, gestation, and lactation. F2 pups were observed through weaning at which time they were euthanized. Observations made during the study included body weights, food consumption, mating and fertility indices, pup and litter survival indices, and histopathology of selected tissues. In the chronic study, except for a slight decrease in survival of high-dose male rats late in the study, survival in all treated groups was comparable to controls. Blood methemoglobin levels were elevated in the mid- and high-dosage groups, while slight anemia was observed in the high-dosage group also. Spleen weights were significantly increased in the high-dosage groups. An accumulation of brown pigment was observed in the cytoplasm of the sinusoidal macrophages or littoral cells of the liver and in the reticuloendothelial cells of the spleen. No treatment-related increase in tumor incidence was observed. In the reproduction study, no consistent pattern of effect from treatment between the F0 and F1 generation was seen in mating, pregnancy, or fertility indices. Thus, administration of PNA at levels which produced significant methemoglobinemia and low-level anemia in the rat and histological changes in the spleen produced no tumors or reproducible effects on reproductive performance.

Aniline Compounds↗
PubMed1986

Reproductive toxicity of ofloxacin.

The reproductive toxicity of (+/-)-9-fluoro-2, 3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de] [1,4]benzoxazine-6-carboxylic acid (ofloxacin, Tarivid), a new antibacterial agent, was investigated in rats and rabbits after oral administration. Neither the male or female fertility nor the reproductive performance of the rats was affected by doses of up to 360 mg/kg. Ofloxacin elicited no evidence of teratogenicity when administered orally during the period of organogenesis to pregnant rats at doses of up to 810 mg/kg, or to pregnant rabbits at doses of up to 160 mg/kg. However, the female rats receiving 810 mg/kg showed salivation, dirty hair coats, soft stools, and decreases of body weight and food intake. The fetuses in the higher dose groups exhibited decreased body weight and retardation of ossification, and those in the highest dose group showed increased mortality and skeletal variations (cervical ribs, shortened 13th ribs). Further investigation of the fetal skeleton revealed that the critical period of the occurrence of skeletal variations was on days 9 and 10 of gestation. The occurrence of cervical ribs and shortened 13th ribs was not an indicator of teratogenicity when ofloxacin was administered at doses of up to 1600 mg/kg during the critical period. Moreover, the shortening of the 13th ribs was the only type of retardation of ossification degree. Decreases of maternal body weight and food intake, and increased mortality of fetuses were observed in rabbits at a dose of 160 mg/kg. In a perinatal and postnatal toxicity study in rats using doses of up to 360 mg/kg, no adverse effects were observed.

Animals↗
PubMed1988

Reproductive toxicity of muroctasin.

The reproductive toxicity of the anomeric mixture of N2-[(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine (MDP-Lys(L18), muroctasin), a new immunomodulator, was investigated in mice and rabbits after subcutaneous injection. Neither the male or female fertility nor the reproductive performance of the mice was affected by doses of up to 1 x 10(4) micrograms/kg. MDP-Lys(L18) elicited no evidence of teratogenicity when injected subcutaneous during the period of organogenesis to pregnant mice at doses of up to 3 x 10(4) micrograms/kg, or to pregnant rabbits at doses of up to 25 micrograms/kg. However, the female mice receiving 3 x 10(4) micrograms/kg showed induration and scabbing of the injection sites. Decrease of maternal body weight and food intake was seen in rabbits at doses of 5 and 25 micrograms/kg. Lacrimation, bloodshot eyes and swelling of eyelid were observed in does at a dose of 25 micrograms/kg. In perinatal and postnatal toxicity study in mice using doses of up to 2 x 10(4) micrograms/kg, a decrease in body weight of dams was seen at a dose of 2 x 10(4) micrograms/kg. Decrease in body weight of pups at birth was observed at a dose of 2 x 10(4) micrograms/kg.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

Oral (drinking water) two-generation reproductive toxicity study of bromodichloromethane (BDCM) in rats.

Bromodichloromethane (BDCM) was tested for reproductive toxicity in a two-generation study in CRL SD rats. Thirty rats/sex/ group/generation were continuously provided BDCM in drinking water at 0 (control carrier, reverse osmosis membrane-processed water), 50,150, and 450 ppm (0, 4.1 to 12.6, 11.6 to 40.2, and 29.5 to 109.0 mg/kg/day, respectively). Adult human intake approximates 0.8 microg/kg/day (0.0008 mg/kg/day). P and F1 rats were observed for general toxicity (viability, clinical signs, water and feed consumption, body weights, organ weights [also three weanling Fl and F2 pups/sex/litter], histopathology [10/sex, 0- and 450-ppm exposure groups]) and reproduction (mating, fertility, abortions, premature deliveries, durations of gestation, litter sizes, sex ratios, viabilities, maternal behaviors, reproductive organ weights [also three weanling Fl and F2 pups/sex/ litter], sperm parameters, and implantations. F1 rats were evaluated for age at vaginal patency or preputial separation. Ten P and F1 rats/sex from the 0- and 450-ppm exposure groups and rats at 50 and 150 ppm with reduced fertility were evaluated for histopathology (gross lesions, testes, intact epididymis, all F1 dams for number of primordial follicles). Developmental parameters in offspring included implantation and pup numbers, sexes, viabilities, body weights, gross external alterations, and reproductive parameters (Fl adults). Toxicologically important, statistically significant effects at 150 and/or 450 ppm included mortality and clinical signs associated with reduced absolute and relative water consumption, reduced body weights and weight gains, and reduced absolute and relative feed consumption (P and F1 rats). Significantly reduced body weights at 150 and 450 ppm were associated with reduced organ weights and increased organ weight ratios (% body and/or brain weight). Histopathology did not identify abnormalities. Small delays in sexual maturation (preputial separation, vaginal patency) and more Fl rats with prolonged diestrus were also attributable to severely reduced pup body weights. Mating, fertility, sperm parameters, and primordial ovarian follicular counts were unaffected. The no-observable-adverse-effect level (NOAEL) and the reproductive and developmental NOAELs for BDCM were at least 50 ppm (4.1 to 12.6 mg/kg/day), 5125 to 15,750 times the human adult exposure level, if delayed sexual maturational associated with severely reduced body weights is considered reproductive toxicity. If considered general toxicity, reproductive and developmental NOAELs for BDCM are greater than 450 ppm (29.5 to 109.0 mg/kg/day), or 36,875 to 136,250 times the human adult exposure level. Regardless, these data indicate that BDCM should not be identified as a risk to human reproductive performance or development of human conceptuses.

Administration, Oral↗