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PubMed1976

[Role of destruction products of tissue macrophages in regulating granulocytopoiesis].

Peripheral blood leukocytosis and an increase of mature forms of neutrophils and monocytes in the bone marrow, as well as an improvement of the oxygen supply of the bone marrow cells (by the data of polarographic studies) followed the intraperitoneal injections of rat peritoneal macrophage destruction products (MDP) to the recipient rats. Analogous changes were obtained in the bone marrow in case of intraperitoneal injection of the cytotoxic quartz dust particles. Having been injected intraperitoneally to donor CBA mice, the MDPs strikingly stimulated the glanulocytopoietic colonies formation in the spleen of the recipient CBA mice X-irradiated with a lethal dose and then injected intravenously with the bone marrow of spleen tissue suspensions obtained from the donors. The results obtained are discussed from the aspect of a possible role of the destroyed tissue macrophages in the formation of a colony-stimulating factor in the auto-control of the phagocytic responses.

Animals↗
PubMed2006

Effects of cevimeline on salivation and thirst in conscious rats.

OBJECTIVE: Intraperitoneal injection of a sialogogue, pilocarpine, at high concentrations induces salivation via peripheral pathways and thirst sensation via central pathways. In this study, we report that the effects of another sialagogue, cevimeline, on salivation and water intake in conscious rats differ from those of pilocarpine. DESIGN: We investigated that effects of peripherally and centrally injected cevimeline on parotid saliva flow rate and water intake in conscious rats. The results were compared with those of pilocarpine. RESULTS: The intraperitoneal injection of cevimeline induced salivation from the parotid gland, but not water intake. In contrast, the intracerebroventricular injection of cevimeline induced water intake without salivation. The concentration of cevimeline needed to induce salivation by intraperitoneal injection was several 10 times that of pilocarpine, but that needed to induce water intake by intracerebroventricular injection was over a 1000 times greater. CONCLUSIONS: The finding that intraperitoneally injected cevimeline induces salivation without inducing water intake, suggests that the effects on the thirst center in the brain are weaker than those of pilocarpine.

Animals↗
PubMed2003

Somatostatin receptor gene transfer inhibits established pancreatic cancer xenografts.

BACKGROUND: Most human pancreatic adenocarcinoma cells do not express somatostatin receptors, and somatostatin does not inhibit the growth of these cancers. We have demonstrated previously that somatostatin inhibits the growth of pancreatic cancers expressing somatostatin receptor subtype-2 (SSTR2), but not receptor-negative cancers. SSTR2 expression may be an important tumor-suppressor pathway that is lost in human pancreatic cancer. We hypothesized that SSTR2 gene transfer would restore the growth-inhibitory response of human pancreatic cancer to somatostatin. MATERIALS AND METHODS: Palpable human pancreatic adenocarcinoma tumors were established on the backs of nude mice by subcutaneous injection of cultured cells (Panc-1). The animals were divided into 5 groups (n = 10/group). Group I served as an untreated control. Group II received an intramuscular injection of the long-acting somatostatin analogue Sandostatin LAR. Group III received Lac-Z expressing adenovirus via intraperitoneal injection. Group IV received SSTR2 expressing adenovirus via intraperitoneal injection. Group V received SSTR2 expressing adenovirus via intraperitoneal injection and an intramuscular injection of Sandostatin LAR. The rate of tumor growth was assessed with calipers. After 28 days, the animals were anesthetized and exsanguanated, and the tumors were excised and weighed. Plasma somatostatin and octreotide levels were measured by radioimmunoassay. Expression of cell-surface somatostatin-receptor protein and known tumor-suppressor proteins was determined by reverse transcriptase-polymerase chain reaction, Western blot, and immunohistochemistry. RESULTS: Systemic delivery of SSTR2-expressing adenovirus by intraperitoneal injection resulted in expression of SSTR2 protein in the subcutaneous human pancreatic cancers. Final tumor weight was significantly decreased in the groups expressing SSTR2 receptors compared to the other 3 groups. Treatment with Sandostatin LAR increased plasma octreotide levels as determined by radioimmunoassay, but had no significant effect on tumor growth. Western blot analysis revealed an up-regulation of the cyclin-dependent kinase inhibitors p27 and p16 in the SSTR2 transfected tumors. CONCLUSIONS: Expression of SSTR2 by human pancreatic cancer causes significant slowing of tumor growth by a mechanism independent of exogenous somatostatin. The mechanism may involve up-regulation of known tumor-suppressor proteins. Restoration of SSTR2 gene expression deserves further study as a potential gene-therapy strategy in human pancreatic cancer.

Adenocarcinoma↗
PubMed1977

In vivo distribution of Pseudomonas aeruginosa slime glycolipoprotein: association with leukocytes.

Intraperitoneal injection of slime glycolipoprotein (GLP) from Pseudomonas aeruginosa induced leukopenia and death of mice, similar to the effect of infection with viable organisms. Differential counts established that the leukopenia was characterized by a decrease in the number of polymorphonuclear leukocytes, followed by death of mice. Mice immunized with GLP survived challenge and responded with a leukocytosis that had a substantial increase in circulating polymorphonuclear leukocytes. Leukocytes from GLP-injected mice were agglutinated by anti-GLP serum, indicating an association between GLP and leukocytes. Other results indicated that 14C-labeled GLP is deposited mainly in the liver. Normal leukocytes labeled with 51Cr were injected intravenously into mice receiving an intraperitoneal injection of GLP. As with GLP, the 51Gr-labeled leukocytes were sequestered in the liver. These results indicate that GLP enters the blood stream and becomes associated mainly with neutrophils, and that the neutrophil-GLP complex is deposited in the liver, possibly accounting for the leukopenia in mice.

Agglutination Tests↗
PubMed1996

Effect of intraperitoneal antimicrobials on the concentration of bacteria, endotoxin, and tumor necrosis factor in abdominal fluid and plasma in rats.

The efficacy of intraperitoneal instillation of antimicrobial agents in eliminating the bacterial contaminant in patients with generalized peritonitis remains controversial. We determined the effect of intraperitoneal instillation of taurolidine or imipenem on mortality, and on the concentration of bacteria, endotoxin, and tumor necrosis factor (TNF) in rats with intraperitoneally injected bacteria. Thirty rats were inoculated intraperitoneally with two enteric bacterial strains, followed by either taurolidine, saline, or imipenem. Abdominal fluid and blood were analyzed at different time intervals. The survival rate was highest in the imipenem group (p < 0.05). The bacterial concentration in abdominal fluid in the taurolidine and imipenem group was lower than in the saline group (p < 0.005), but the concentration in the imipenem group was lowest (p < 0.005). The endotoxin concentration in abdominal fluid and plasma in the taurolidine group was lower than in the other two groups (p < 0.05). The TNF concentration in abdominal fluid and plasma in the taurolidine group was lower than in the saline group (p < 0.05), whereas the concentration in the imipenem group was higher (p < 0.005). We conclude that topically applied taurolidine in rats with intraperitoneally injected bacteria may have a weak antibacterial effect, and lowered concentrations of endotoxin and TNF. Topically applied imipenem had a profound bactericidal activity but induced endotoxin and TNF release.

Abdomen↗
PubMed1994

In vivo production of heat shock protein in mouse peritoneal macrophages by administration of lipopolysaccharide.

The in vivo production of heat shock protein was studied by administration of bacterial lipopolysaccharide (LPS) into mice. Heat shock protein 70 was detected in the extract of adherent peritoneal cells from mice injected intraperitoneally with LPS by using the immunoblotting method. The expression of heat shock protein 70 was found 2 days after injection of LPS and reached its peak 4 days after injection. The intraperitoneal injection of LPS induced the expression of heat shock protein 70, whereas its subcutaneous injection did not. The in vivo production of heat shock protein 70 was inhibited by administration of LPS together with quercetin, an inhibitor of accumulation of heat shock protein 70 mRNA. Tumor necrosis factor alpha enhanced LPS-induced heat shock protein production in vivo. There was a decrease of gamma delta T cells in the peritoneal cavity of mice injected intraperitoneally with LPS. It was suggested that bacterial LPS is a stressful agent which induces the in vivo heat shock protein response, and its administration leads to the production of heat shock protein 70 in peritoneal macrophages.

Animals↗
PubMed2006

[Effects of norcantharidin on angiogenesis of human gallbladder carcinoma and its anti-angiogenic mechanisms].

OBJECTIVE: To investigate the effects of norcantharidin (NCTD) on angiogenesis of human gallbladder carcinoma and its anti-angiogenic mechanisms. METHODS: Human gallbladder carcinoma cells of the line GBC-SD were cultured. BALB/c nude mice were inoculated subcutaneously with the GBC-SD cells and then randomly divided into 6 groups: NCTD group, injected intraperitoneally with 1/5 of the LD(50) of NCTD twice a week for 6 weeks; 5-fluorouracil (5-FU) group, injected intraperitoneally with 1/5 of the LD(50) of 5-FU twice a week for 6 weeks; endostatin (ES) group, intraperitoneally with ES; NCTD + 5-FU group, injected intraperitoneally with 1/5 of the LD(50) of NCTD and 1/5 of the LD(50) of 5-FU twice a week for 6 weeks; NCTD + ES group, injected intraperitoneally with 1/5 of the LD(50) of NCTD and ES twice a week for 6 weeks; and normal saline (NS) group (control group), injected with NS. The mice were killed in the 7th week. The tumors were taken out to measure their volumes and undergo microscopy. SABC method of immunohistochemistry was used to measure the microvessel density (MVD) and the protein expression of the angiogenesis-related factors: proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), angiopoietin (Ang)-2, thrombospondin (TSP), and tissue inhibitor of metalloprotease (TIMP)(2). Suspension of single tumor cell was prepared to examine the cell apoptosis by flow cytometry. RT-PCR was used to examine the mRNA expression of PCNA, VEGF, Ang-2, TSP, and TIMP2. RESULTS: (1) The MVD of the NCTD group was 4.12 +/- 1.4, significantly lower than those of the 5-FU group (15.8 +/- 5.9) and control group (17.6 +/- 3.2) (both P < 0.01), but not significantly different from those of the NCTD + 5-FU group (3.8 +/- 1.7), ES group (4.5 +/- 2.1), and NCTD + ES group (2.9 +/- 1.5) (all P > 0.05). The mice treated with NCTD showed significantly smaller tumor volume, lower PCNA protein expression, higher apoptotic rate, and higher PCNA/apoptosis ratio (P < 0.05 or P < 0.01), and significant correlation between MVD and tumor volume and between MVD and PCNA/apoptosis ratio (both P < 0.05). (2) The protein expression of VEGF and of Ang-2 of the NCTD group were both significantly lower than those of the control and 5-FU groups (all P < 0.01), however, not significantly different from those of the ES, NCTD + 5-FU, and NCTD + ES groups; and the protein expression of TSP and of TIMP2 of the NCTD group were both significantly higher than those of the control and 5-FU groups (all P < 0.01), however, not significantly different from those of the ES, NCTD + 5-FU, and NCTD + ES groups. MVD was positively correlated with VEGF and Ang-2 expression and negatively correlated with the expression of TSP and TIMP2 (all P < 0.05). (3) In comparison with the control group, the mRNA expression of VEGF and of Ang-2 of the tumor cells of the NCTD group were both significantly lower and the mRNA expression of TIMP2 was significantly higher. CONCLUSION: NCTD down-regulates the expression of the angiogenic factors, such as VEF|GF and Ang-2, and up-regulates the expression of the anti-angiogenic factors, such as TDP and TIMP2, thus inhibiting the angiogenesis in tumor, such as human gallbladder carcinoma, and further inhibiting the growth of tumor.

Angiostatins↗
PubMed1987

Observations on the mechanism and location of ascites reabsorption in man.

Animal data indicate that ascites is reabsorbed by a lymphatic mechanism and that these vessels are subdiaphragmatic in location. We evaluated the relative role of lymphatics in ascites reabsorption in man by comparing the ascites clearance and plasma appearance rates of intraperitoneally injected radiolabeled albumin to those of intraperitoneally injected labeled autologous red blood cells, which require, owing to their large size, lymphatic removal, in patients with cirrhosis and ascites. To evaluate the location of reabsorption, we repeated these measurements after replacing ascites in the subdiaphragmatic region with 500-1000 ml of intraperitoneally injected air, reasoning that this maneuver should slow or eliminate ascites reabsorption occurring at this site. We found that the transfer rates of albumin and red cells out of ascites were similar and that creation of pneumoperitoneum did not influence these rates. These data confirm that ascites protein reabsorption occurs via a lymphatic mechanism in man. They suggest, however, that these vessels may not be subdiaphragmatic in location.

Absorption↗
PubMed1976

A serum facted by newborn calf serum.

An intraperitoneal injection of newborn calf serum (NBCS) into CRF Swiss mice causes an inflammatory reaction characterized by an increase in the number of macrophages in the peritoneal cavity and a concomitant monocytosis. The serum of such mice contains a monocytosis-inducing factor, as demonstrated by the intravenous injection of serum collected 18 (CalS18) and 24 hr (CalS24) after the intraperitoneal injection of NBCS. Serum from normal untreated mice, from mice given an intraperitoneal injection of sterile pyrogen-free saline, which does not cause an inflammatory reaction, or from mice 72 hr after an intraperitoneal injection of NBCS, when the inflammatory reaction has subsided, does not cause a monocytosis in test mice. Intravenous injection of CalS18 causes not only a monocytosis but also an increase in the number of promonocytes and bone marrow monocytes, suggesting an increased in the number of promonocytes and bone marrow monocytes, suggesting an increased production of monocytes. The effect of CalS18, CalS24 and CalS18 filtrate is specific for the mononuclear phagocytes, since only non-significant increases in the numbers of lymphocytes and granulocytes were observed. The active factor in CalS18 was shown to be different from the monocytosis-inducing factor present in NBCS. The monocytosis-inducing factor in CalS18 passes through an ultrafiltration membrane with an exclusion limit of 50,000 Daltons, so that the molecular weight must be below this value.

Animals↗
PubMed2003

Ethanol increases extracellular dopamine concentration in the ventral striatum in C57BL/6 mice.

BACKGROUND: Mesolimbic dopamine is thought to play a role in the reinforcing properties of ethanol, but ethanol-induced changes in extracellular dopamine in the ventral striatum have not been well characterized in mouse models. METHODS: Two experiments were used to characterize the pharmacodynamic response of ethanol in the ventral striatum in C57BL/6 mice. The first experiment determined the effect of ethanol on ventral striatal dopamine in male and female mice after intraperitoneal injection of either 2.0 g/kg ethanol or saline. The second experiment was a replication in males, except that the mice were habituated to intraperitoneal injections before the dialysis experiment. RESULTS: Distinct patterns of dopamine activity in response to ethanol were demonstrated in male and female C57BL/6 mice. A significant increase in dialysate dopamine relative to saline injection was observed in females but not in males. With habituation to intraperitoneal injection before the dialysis experiment, ethanol administration caused a significant dopamine response in males as well. A linear decline was observed in dialysate ethanol concentrations after the peak concentration was reached. Concurrent analysis of the time course of dopamine and ethanol content showed that the dopamine response declined significantly faster than the ethanol concentrations. CONCLUSIONS: The C57BL/6 mouse strain is a justifiable model system for studying the mechanisms involved in ethanol regulation of mesolimbic dopamine activity. Habituation to intraperitoneal injection should be used in male C57BL/6 mice for experiments in which the dopamine response is measured after intraperitoneal injection of a drug. The dissociation between dopamine and ethanol may indicate an acute neural adaptation to ethanol-induced dopamine response in the ventral striatum after a single ethanol injection.

Animals↗
PubMed2003

[The change of cryptdin-4 mRNA expression in the intestine of mouse with experimental pancreatitis].

OBJECTIVE: experimental pancreatitis and explore the mechanism of bacterial translocation at the molecular level in mice with severe acute pancreatitis. METHODS: Thirty-six ICR mice were randomly divided into 6 groups with 6 mice in each group. The animals in the experimental groups (from A to E) received seven intraperitoneal injections of caerulein (50 microg/kg body weight) at hourly intervals over 6 hours, and were killed at 9, 18, 24, 48 and 72 hours after the first injection. The control group (F) received intraperitoneal injection of the same volume of saline, and the animals were killed at the 18th hour after the first injection. Blood and pancreatic tissue samples were obtained after the animals were killed. Amylase and pancreatic pathological alterations were observed. The ileum sequential segments were removed from each mouse. The amplification products of RT-PCR were electrophoresed and the images were analyzed by UVI software. RESULTS: Acute necrotizing pancreatitis in ICR mice were induced by the intraperitoneal injection of caerulein at large doses. Markedly pathological lesions were observed at the 18th hour after the first injection of caerulein. And, intestinal cryptdin-4 mRNA expression was down regulated slightly at the 9th hour and most markedly at the 18th hour (P < 0.05). After 24 hours, the cryptdin-4 mRNA expression recovered to the normal level gradually. CONCLUSION: Acquired cryptdin-4 deficiency may play an important role in the pathogenesis of bacterial tanslocation in acute necrotizing pancreatits.

Acute Disease↗
PubMed1995

Nephrotoxicities of aluminium and/or cadmium-metallothionein in rats: creatinine excretion and metabolism of selected essential metals.

The effects of exposure to aluminium (Al) and cadmium (Cd) on urinary creatinine and protein excretion, and the concentrations of calcium, magnesium and copper in kidney and urine were studied in 32 male adult Wistar rats. The animals were divided into 8 groups, groups 1-4 given a calcium-deficient diet (0.01%, i.e. 0.01 g calcium/100 g diet weight) and groups 5-8 a calcium-adequate diet (0.9%) for 6 weeks. Single daily intraperitoneal injections of AlCl3 (10.8 mg Al/kg body weight, per day) were done on 6 consecutive days to groups 3, 4, 7 and 8 during the last week of the experiment. One single intraperitoneal injection of cadmium-metallothionein (Cd-MT, 0.4 mg Cd/kg) was administered 12 hr before the final Al dose to groups 2, 4, 6, and 8 and the rats were sacrificed 47 hr after the Cd-MT injection. The rate of creatinine clearance was significantly lower in rats injected intraperitoneally with either Cd-MT or Al, and the concentrations of magnesium and calcium in urine were lower in rats administered both Al and Cd-MT as compared to those in control groups. Histological examination showed that Al was toxic to the kidney tubule cells of rats, however, an adequate supply of calcium in food protected to some extent the renal tubules from Al toxicity as indicated by a higher creatinine clearance, and there was also less tubule damage as shown by histological examination. The copper concentrations in kidney tissue were lower in groups treated with either Al or Cd-MT.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum↗
PubMed1994

[Effect of E. coli endotoxin and D-galactosamine on pathophysiology in rat lungs].

The effects of repeated intravenous injection of E. coli endotoxin (ETX) and intraperitoneal injection of D-galactosamine (GAL), which decreases the circulating level of alpha 1-antitrypsin, on the pathophysiology of chronic lung injury was studied in rats. Four groups were prepared as follows for 8 weeks. Group 1 (control): Intravenous injection of saline. Group 2: Intravenous injection of ETX (2 mg/kg) once a week. Group 3: Intraperitoneal injection of GAL (200 mg/kg), 2 times daily on 3 consecutive days each week. Group 4: Injection of both ETX and GAL, at the same dosages as used in groups 2 and 3. Total lung capacity and static lung compliance divided by weight were high in the ETX group and the ETX + GAL group, comparative when compared with those in the control and GAL groups, even though weight gain rates in the ETX + GAL group was less than in other groups. Mean linear intercept of rats in the ETX + GAL group was significantly greater than in other groups. These results suggest that ETX + GAL-treated rats have more emphysematous changes in pulmonary function and structure.

Animals↗
PubMed2001

Staphylococcal enterotoxin B induces fever, brain c-Fos expression, and serum corticosterone in rats.

The paraventricular nucleus of the hypothalamus (PVH) occupies a pivotal point within the network of brain nuclei coordinating critical host-defense responses. In mice, T cell-dependent immune stimuli, including the bacterial superantigen staphylococcal enterotoxin B (SEB), can activate the PVH. To determine whether T cell-dependent immune stimuli activate the PVH in rats, we assessed plasma corticosterone (Cort) levels, fever responses, and c-Fos expression in the PVH in animals treated with intraperitoneal injections of SEB. In animals with previously implanted abdominal thermisters, intraperitoneal injection of 1 mg/kg SEB resulted in a significant rise in body temperature, with a latency of 3.5-4 h. In separate animals, intraperitoneal injection of 1 mg/kg SEB resulted in a significant elevation of plasma Cort and induced c-Fos expression in parvocellular neurons within the PVH. These results support the idea that T cell-dependent immune stimuli activate brain pathways mediating host-defense responses such as fever and neuroendocrine changes.

Animals↗
PubMed2000

Fish DNA vaccine against infectious hematopoietic necrosis virus: efficacy of various routes of immunisation.

The DNA vaccine, pIHNVw-G, contains the gene for the glycoprotein (G) of the rhabdovirus infectious hematopoietic necrosis virus (IHNV), a major pathogen of salmon and trout. The relative efficacy of various routes of immunisation with pIHNVw-G was evaluated using 1.8 g rainbow trout fry vaccinated via intramuscular injection, scarification of the skin, intraperitoneal injection, intrabuccal administration, cutaneous particle bombardment using a gene gun, or immersion in water containing DNA vaccine-coated beads. Twenty-seven days after vaccination neutralising antibody titres were determined, and 2 days later groups of vaccinated and control unvaccinated fish were subjected to an IHNV immersion challenge. Results of the virus challenge showed that the intramuscular injection and the gene gun immunisation induced protective immunity in fry, while intraperitoneal injection provided partial protection. Neutralising antibodies were not detected in sera of vaccinated fish regardless of the route of immunisation used, suggesting that cell mediated immunity may be at least partially responsible for the observed protection.

Administration, Buccal↗
PubMed1979

Delayed-type hypersensitivity and acquired cellular resistance in mice immunized with killed Listeria monocytogenes and adjuvants.

Delayed-type hypersensitivity (DH) and acquired cellular resistance (ARC) to Listeria monocytogenes in mice was studied following immunization with killed bacteria in combination with Freund's complete adjuvant or the adjuvant dimethyldioctadecylammonium bromide (DDA). Intracutaneous or intraperitoneal injections of killed listeria mixed with Freund's complete adjuvant did neither result in DH nor in ACR. Intracutaneous injections of killed listeria and DDA resulted in an antigen-dose dependent DH but not in ACR. Intraperitoneal injections of listeria and DDA, however, induced ACR but no DH. Optimal conditions for the induction of ACR were simultaneous intraperitoneal injection of 15 mg DDA/kg body weight and 10(7) or 10(8) listeria. The optimal interval between immunization and challenge was 7 days. No protection was found against challenge with a lethal dose of Salmonella enteritidis, suggesting that the protection is specific. Intraperitoneal injection of mice with DDA resulted in inhibition of phagosome-lysosome fusion in macrophages harvested 24 h later. Interference with macrophage activity is discussed as one of the possible mechanisms for the adjuvant effect of DDA.

Adjuvants, Immunologic↗
PubMed2005

Aldehyde dehydrogenase 2 activity affects symptoms produced by an intraperitoneal acetaldehyde injection, but not acetaldehyde lethality.

Aldehyde dehydrogenase 2 (ALDH2) is an important enzyme that oxidizes acetaldehyde. Approximately 45% of Chinese and Japanese individuals are inactive ALDH2 phenotype; acute acetaldehyde toxicity has not been evaluated in these populations. We compared the acute acetaldehyde toxicity between wild-type (Aldh2+/+) and Aldh2-inactive transgenic (Aldh2-/-) mice who were administered an intraperitoneal (ip) injection of a single dose of acetaldehyde. This comparison was made based on the LD(50) values of acetaldehyde and the symptoms following the ip injection. Blood acetaldehyde level was measured in the 400 mg/kg dose group. Immediately after administration of acetaldehyde, the mice exhibited hypoactivity and staggering gait. Subsequently, symptoms such as pale skin, prone position, coma, and abnormal deep respiration were observed. In cases of death, dyspnea, wheezing, and hypothermia were observed from 15 to 30 min after the administration. In cases of survival, crouching, bradypnea, flushing and piloerection were observed. Significant latency of symptom recovery was found in the Aldh2+/- mice as compared with the Aldh2+/+ mice; however, no statistical difference was observed in the acetaldehyde LD(50) values. This might be attributable to the absence of a significant difference in the blood acetaldehyde concentrations in both mice during the first 0-15 min following administration; however, acetaldehyde elimination delay was observed in the Aldh2-/- mice as compared with the Aldh2+/+ mice. Acetaldehyde toxicity difference was observed between the Aldh2+/+ and Aldh2-/- mice; however, no difference in acetaldehyde lethality was observed by administration of a single dose of an ip acetaldehyde injection.

Acetaldehyde↗
PubMed2000

Tannins protect against skin tumor promotion induced by ultraviolet-B radiation in hairless mice.

We recently showed that Tarapod tannic acid (TA), a hydrolyzable tannin extracted from the pods of the Tara tree (Caesalpinia spinosa), was more effective than other tannins tested at inhibiting ultraviolet-B (UV-B)-stimulated hydrogen peroxide activity (an indirect measure of free radicals) in the skin of hairless mice. We also found that Tarapod TA inhibited UV-B-induced ornithine decarboxylase activity and UV-B-stimulated DNA synthesis, two biochemical markers linked to the skin tumor-promoting ability of this physical carcinogen. For this reason, we examined the effect of topical application, force feeding (gavage), and intraperitoneal injections of Tarapod TA on mouse skin chronically treated with UV-B light. Mice were initiated by a single topical application of 7,12-dimethylbenz[a]anthracene (50 nmol) and promoted by two weekly treatments with UV-B light (250 mJ/cm2) for 25 weeks. Topical application of Tarapod TA, 20 minutes before irradiation, resulted in a dose-dependent inhibition of tumor incidence (number of mice with tumors) and tumor yield (number of tumors/mouse), with 8 mg of TA inhibiting tumor yield by 70% at Week 25. Intraperitoneal injections of low doses (10 mg/kg mouse body wt), but not of high doses (25 mg/kg body wt), of TA afforded protection against UV-B-induced papillomas. However, the protection by intraperitoneal injection was lower than that observed by topical application: 10 mg/kg body wt of TA reduced tumor yield by 55%. The force feeding of 10 mg of Tarapod TA before irradiation failed to significantly inhibit the yield of tumors at the end of the experiment but delayed tumor appearance by six weeks. These results suggest that plant tannins administered topically or injected intraperitoneally reduce the tumor-promoting effects of UV-B radiation and thus could be useful photoprotectants.

Administration, Oral↗