Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The quantitative distributions of aspartate aminotransferase and glutaminase were mapped in subregions of olfactory bulb and cochlear nucleus of rat, and were compared with similar data for retina and with the distributions of their substrate and product amino acids aspartate, glutamate, and glutamine. The distributions of both enzymes paralleled that of aspartate in the olfactory bulb and that of glutamate in the cochlear nucleus. In retina (excluding inner segments), there were similarities between aspartate aminotransferase and both glutamate and aspartate distributions. The distribution of gamma-aminobutyrate (GABA) was similar to those of both enzymes in olfactory bulb, to aspartate aminotransferase in cochlear nucleus, and to glutaminase in retina (excluding inner segments). The results are consistent with significant involvement of aspartate aminotransferase, especially the cytosolic isoenzyme, and glutaminase in accumulation of the neurotransmitter amino acids glutamate, aspartate, and GABA, although with preferential accumulation of different amino acids in different brain regions.
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PMID:Aspartate aminotransferase and glutaminase activities in rat olfactory bulb and cochlear nucleus; comparisons with retina and with concentrations of substrate and product amino acids. 791 16

Homogenates of specific brain regions of three sensory systems (auditory, olfactory, and visual) were prepared from pigmented Long-Evans Hooded rats and assayed for amino acid concentrations and activities of glutaminase, aspartate aminotransferase (total, cytosolic, and by difference, mitochondrial), malate dehydrogenase, lactate dehydrogenase, and choline acetyltransferase. Comparing the quantitative distributions among regions revealed significant correlations between AAT and aspartate, between glutaminase and glutamate, between glutamate and glutamine, and between AAT plus glutaminase, or glutaminase alone, and the sum of aspartate, glutamate, and GABA, suggesting a metabolic pathway involving the synthesis of a glutamate pool as precursor to aspartate and GABA. Of the inhibitory transmitter amino acids, GABA concentrations routinely exceeded those of glycine, but glycine concentrations were relatively high in brainstem auditory structures.
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PMID:Amino acid concentrations and selected enzyme activities in rat auditory, olfactory, and visual systems. 878 12

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
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PMID:NTP Toxicology and Carcinogenesis Studies of Monochloroacetic Acid (CAS No. 79-11-8) in F344/N Rats and B6C3F1 Mice (Gavage Studies). 1263 63

1,2,3-Trichloropropane is a colorless liquid used as a paint and varnish remover, solvent, and degreasing agent, and as a crosslinking agent in the synthesis of polysulfides and hexafluoropropylene. 1,2,3-Trichloropropane may be found as an impurity in certain nematocides and soil fumigants and as a contaminant of drinking and ground water. Studies on the toxic and carcinogenic effects of 1,2,3-trichloropropane were initiated because of the close structural relationship of this chemical to other short-chain halogenated compounds that were demonstrated to be carcinogenic in experimental animals, and because of the potential for human exposure. Toxicology and carcinogenicity studies were conducted by administering 1,2,3-trichloropropane (greater than 99% pure) in corn oil by gavage to groups of F344/N rats and B6C3FI mice for 17 weeks and 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium strains, mouse lymphoma cells, and Chinese hamster ovary cells. 17-Week Studies: Groups of 20 male and 20 female rats received 1,2,3-trichloropropane in corn oil by gavage at doses of 8, 16, 32, 63, 125, or 250 mg/kg body weight 5 days per week for up to 17 weeks; 30 male and 30 female rats received corn oil alone and served as controls. Animals were evaluated at 8 or 17 weeks. All rats in the 250 mg/kg groups died by week 5. One male and four female rats in the 125 mg/kg groups died during the study. The mean body weight gains and final mean body weights of males receiving 63 mg/kg and of males and females receiving 125 mg/kg were lower than those of the controls. Hematocrit values, hemoglobin concentrations, and erythrocyte counts decreased with dose in males and females. Serum alanine aminotransferase, aspartate aminotransferase, and sorbitol dehydrogenase activities were significantly increased in some female rats receiving 125 mg/kg. Serum pseudocholinesterase activity decreased with dose in females. Increases in kidney and liver weights were related to chemical administration. The principal toxic lesions associated with the administration of 1,2,3-trichloropropane to rats were hepatocellular necrosis, karyomegaly, and biliary hyperplasia of the liver; renal tubule necrosis, regeneration, and karyomegaly of the kidney; and necrosis and inflammation of the nasal olfactory and respiratory epithelium. Groups of 20 male and 20 female mice received 1,2,3-trichloropropane in corn oil by gavage at doses of 8, 16, 32, 63, 125, or 250 mg/kg 5 days per week for up to 17 weeks; 30 male and 30 female mice received corn oil alone and served as controls. Sixteen male and seven female mice in the 250 mg/kg groups died by week 4. The final mean body weights and mean body weight gains of dosed mice were similar to those of the controls, except those of 250 mg/kg males, which were lower than those of controls. The principal toxic lesions associated with the administration of 1,2,3-trichloropropane were hepatocellular necrosis and karyomegaly of the liver; necrosis, regeneration, and hyperplasia of the bronchiolar epithelium in the lung; and acanthosis (hyperplasia) and hyperkeratosis of the forestomach epithelium. 2-Year Studies: Groups of 60 male and 60 female rats received 0, 3, 10, or 30 mg 1,2,3-trichloropropane/kg body weight in corn oil by gavage 5 days per week for up to 104 weeks. Selection of 30 mg/kg as the high dose in these studies was based on the following chemical-related effects in the 17-week studies: deaths and liver and kidney lesions at 125 and 250 mg/kg and reduced final mean body weights and mean body weight gains at 63 mg/kg or greater. Groups of 60 male and 60 female mice received 0, 6, 20, or 60 mg 1,2,3-trichloropropane/kg body weight in corn oil by gavage 5 days per week for up to 104 weeks. Selection of 60 mg/kg as the high dose was based on chemical-related deaths and lesions of the liver, lung, and forestomach at 125 and 250 mg/kg in the 17-week studies. 15-Month Interim Evaluations: Up to 10 rats and 10 mice from each dose group were evaluated at 15 months. Absolute and relative liver and kidned kidney weights of dosed rats were significantly greater than those of the controls. Chemical-related nonneoplastic lesions and neoplasms of the forestomach, oral mucosa, pancreas (males), kidney, mammary gland (females), preputial gland, and clitoral gland were observed in dosed rats. Chemical-related nonneoplastic lesions and neoplasms of the forestomach and liver (females) were observed in dosed mice. Survival and Body Weight in the 2-Year Studies: Survival of male and female rats receiving 10 or 30 mg/kg 1,2,3-trichloropropane was significantly lower than that of controls. Two-year survival rates of male rats were: control, 34/50; 3 mg/kg, 32/50; 10 mg/kg, 14/49; 30 mg/kg, 0/52; and of females were: 31/50, 30/49, 8/52, 0/52. At 30 mg/kg, survival was markedly reduced due to chemical-related neoplasms, and survivors were killed in weeks 67 (females) or 77 (males). Final mean body weights of 30 mg/kg rats were 13% lower for males and 12% lower for females than those of controls; mean body weights of 3 and 10 mg/kg rats were similar to controls. Survival rates of mice receiving 6, 20, or 60 mg/kg 1,2,3-trichloropropane were also significantly lower than those of controls. Two-year survival rates of male mice were: 42/52, 18/51, 0/54, 0/56; and of female mice were: 41/50, 13/50, 0/51, 0/55. Because of reduced survival at 20 and 60 mg/kg due to chemical-related neoplasms, survivors were killed in weeks 73 (60 mg/kg females), 79 (60 mg/kg males), or 89 (20 mg/kg males and females). Final mean body weights were 16% lower for 60 mg/kg males, 18~ lower for 60 mg/kg females, and 13% lower for 20 mg/kg males than those of controls. Final mean body weights of 6 mg/kg males and females and 20 mg/kg females were similar to controls. Neoplasms and Nonneoplastic Lesions in the 2-Year Studies: Administration of 1,2,3-trichloropropane to rats induced benign and malignant neoplasms of the oral mucosa (pharynx and tongue), forestomach, and preputial and clitoral glands in males and females; benign neoplasms of the exocrine pancreas and kidney in males, and malignant neoplasms of the mammary gland in females. The incidences of squamous cell papillomas and carcinomas of the oral mucosa were significantly increased in 10 and 30 mg/kg rats, while the incidences of squamous cell papillomas or carcinomas (combined) of the forestomach were significantly increased in all dosed groups. The incidence of pancreatic acinar adenoma was significantly increased in dosed males, but not in dosed females. Similarly, the incidence of adenoma of the kidney was significantly increased in 10 and 30 mg/kg male rats only. The incidences of adenoma or carcinoma (combined) of the preputial gland in 30 mg/kg males and of the clitoral gland in 10 and 30 mg/kg females (homologous organs) were significantly increased. The incidence of adenocarcinoma of the mammary gland was significantly increased in the 10 and 30 mg/kg females. The incidences of Zymbal's gland carcinomas were increased in 30 mg/kg males and females. Adenocarcinomas of the intestine occurred in small numbers of dosed rats and may have been chemical related. In mice, the incidence of squamous cell carcinoma of the oral mucosa was significantly increased only in 60 mg/kg females. In contrast, the incidences of squamous cell papilloma and carcinoma of the forestomach were significantly increased in all groups of dosed mice. The incidences of hepatocellular adenoma or carcinoma (combined) were significantly increased in all dosed groups of males and 60 mg/kg females. The incidences of harderian gland adenoma were significantly increased in 20 mg/kg males and in 60 mg/kg males and females. The incidences of uterine adenoma, adenocarcinoma, and stromal polyp were significantly increased in 60 mg/kg females. Genetic Toxicology: 1,2,3-Trichloropropane was mutagenic in vitro in the presence of S9 metabolic activation. At two laboratories, positive responses were obtained for mutagenicity in Salmonella typhimurium strains TA97, TA98, TA100, and TA1535 in the presence of S9; no mutagenic activity was observed in TA1537, with or without S9. 1,2,3-Trichloropropane induced trifluorothymidine resistance in L5178Y mouse lymphoma cells with, but not without, S9. In cultured Chinese hamster ovary cells, sister chromatid exchanges and chromosomal aberrations were induced by 1,2,3-trichloropropane; however, significant increases in the endpoints of both cytogenetic effects occurred only in the presence of S9. Conclusions: Under the conditions of these 2-year gavage studies, there was clear evidence of carcinogenic activity of 1,2,3-trichloropropane in male F344/N rats based on increased incidences of squamous cell papillomas and carcinomas of the oral mucosa and forestomach, adenomas of the pancreas and kidney, adenomas or carcinomas of the preputial gland, and carcinomas of the Zymbal's gland. Adenomatous polyps and adenocarcinomas of the intestine may have been related to chemical administration. There was clear evidence of carcinogenic activity of 1,2,3-trichloropropane in female F344/N rats based on increased incidences of squamous cell papillomas and carcinomas of the oral mucosa and forestomach, adenomas or carcinomas of the clitoral gland, adenocarcinomas of the mammary gland, and carcinomas of the Zymbal's gland. Adenocarcinomas of the intestine may have been related to chemical administration. There was clear evidence of carcinogenic activity of 1,2,3-trichloropropane in male B6C3F1 mice based on increased incidences of squamous cell papillomas and carcinomas of the forestomach, hepatocellular adenomas or carcinomas of the liver, and harderian gland adenomas. Squamous cell papillomas of the oral mucosa may have been related to chemical administration. There was clear evidence of carcinogenic activity of 1,2,3-trichloropropane in female B6C3F1, mice based on increased incidences of squamous cell carcinomas of the oral mucosa, squamous cell papillomas and carcinomas of the forestomach, hepatocellular adenomas or carcinomas of the liver, harderian gland adenomas, and uterine adenomas, adenocarcinomas, and stromal polyps. Nonneoplastic lesions associated with exposure to 1,2,3-trichloropropane included increased severity of nephropathy in male rats and increased incidences of basal cell and squamous hyperplasia of the forestomach, acinar hyperplasia of the pancreas, renal tubule hyperplasia, and preputial or clitoral gland hyperplasia in male and female rats. Increased incidences of squamous hyperplasia of the forestomach and eosinophilic foci in the liver in male and female mice were chemical related. Synonyms: Allyl trichloride, glycerol tnchlorohydrin, glyceryl tnchlorohydrin, trichlorohydrin
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PMID:NTP Toxicology and Carcinogenesis of 1,2,3-Trichloropropane (CAS No. 96-18-4) in F344/N Rats and B6C3F1 Mice (Gavage Studies). 1269 52

The xylenes are commonly used industrial solvents that have been shown to inhibit cytochrome P-450 (CYP450) activities in an organ- and isozyme-specific pattern. This study examined the dose-response and durational effects of m-xylene inhalation on cytochrome P-450 activities in the respiratory tract and liver as well as the effects of these CYP450 alterations on 1-nitronaphthalene (1-NN)-induced respiratory or hepatic toxicity. After m-xylene inhalation exposure there was a dose-related inhibition of all nasal mucosa CYPs examined. At 300 ppm, inhibition was sustained up to 2 days after exposure, but on day 5 all CYP activities were increased. There was also dose-related inhibition of lung CYPs 2B1, 2E1, and 4B1. The activities of these CYPs returned to those of control by day 2 but lung CYP 2B1 was increased 5 days following m-xylene exposure. Hepatic CYP 2E1 activity was increased immediately following m-xylene exposure (300 ppm). CYP 2B1 and CYP 1A2 activities were increased through day 2, all activities returning to control values 5 days postexposure. 1-NN treatment caused severe respiratory toxicity that was prevented by prior m-xylene exposure. Lactate dehydrogenase (LDH) and protein were increased in nasal lavage fluid (NLF) but gamma-glutamyl transferase (GGT) was unchanged. m-Xylene coexposure prevented or ameliorated the increases in LDH and protein but increased GGT. 1-NN-induced increases in bronchoalveolar lavage fluid (BALF) LDH and GGT were attenuated by m-xylene. 1-NN caused pronounced histopathological changes in both respiratory and olfactory regions of the nasal mucosa. Lesions in both regions were characterized by acute epithelial necrosis and exfoliation and suppurative exudate in the airways. These changes were prevented by m-xylene coexposure. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were not changed in animals exposed to 1-NN but were increased by m-xylene coexposure. Low-level m-xylene exposure organ-selectively altered CYP450 isozyme activities and subsequent 1-NN toxicity.
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PMID:Inhibition of rat respiratory-tract cytochrome P-450 activity after acute low-level m-xylene inhalation: role in 1-nitronaphthalene toxicity. 1520 73

Subchronic oral toxicity of 1,4-dioxane was examined by administering 1,4-dioxane in drinking water at 6 different concentrations of 0 (control), 640, 1,600, 4,000, 10,000 or 25,000 ppm (wt/wt) to F344 rats and BDF(1)mice of both sexes for 13 weeks. Food and water consumption and terminal body weight were decreased dose-dependently in rats and mice. A dose-dependent increase in the relative weights of kidney and lung was noted in rats and mice, while the relative liver weight was increased only in rats. Increases in plasma levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and a decrease in plasma glucose were noted primarily in the rats and mice dosed 25,000 ppm. Histopathological examination revealed that 1,4-dioxane affected the upper and lower respiratory tracts, liver, kidneys and brain in rats, while only the former two organs were affected in mice. Nuclear enlargement occurred in the respiratory, olfactory, tracheal and bronchial epithelia of the 1,4-dioxane-dosed rats and mice. The 1,4-dioxane-induced hepatic lesions were characterized by centrilobular swelling and necrosis in rats and mice and by glutathione S-transferase placental form (GST-P)-positive altered hepatocellular foci in rats, which are known as preneoplastic lesions. A no-observed-adverse-effect-level (NOAEL) was determined at 640 ppm for both rats and mice, since the nuclear enlargement in the nasal respiratory epithelium and the centrilobular swelling of hepatocytes in rats and the nuclear enlargement in the bronchial epithelium in mice were observed at 1,600 ppm. The NOAEL value corresponded to the estimated 1,4-dioxane intake of 52 mg/kg/day in rats and 170 mg/kg/day in mice.
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PMID:Thirteen-week oral toxicity of 1,4-dioxane in rats and mice. 1854 6

Tetralin is used as an industrial solvent primarily for naphthalene, fats, resins, oils, and waxes; as a solvent and stabilizer for shoe polishes and floor waxes; as a solvent for pesticides, rubber, asphalt, and aromatic hydrocarbons (e.g., anthracene); as a dye solvent carrier in the textile industry; as a substitute for turpentine in lacquers, paints, and varnishes; in paint thinners and as a paint remover; in alkali-resistant lacquers for cleaning printing ink from rollers and type; as a constituent of motor fuels and lubricants; for the removal of naphthalene in gas distribution systems; and as an insecticide for clothes moths. Tetralin was nominated by the National Cancer Institute for carcinogenicity and disposition studies because of its structure, high production volume, and high potential for worker and consumer exposure. Male and female F344/N rats and B6C3F1 mice were exposed to tetralin (at least 97% pure) by inhalation for 2 weeks, 3 months, or 2 years; male NCI Black Reiter (NBR) rats were exposed to tetralin by inhalation for 2 weeks. Male NBR rats do not produce 2u-globulin; the NBR rats were included to study the relationship of 2u-globulin and renal lesion induction. Genetic toxicology studies were conducted in Salmonella typhimurium, Escherichia coli, and mouse peripheral blood erythrocytes. 2-WEEK STUDY IN RATS: Groups of five male (F344/N and NBR) and five female (F344/N) rats were exposed to tetralin at air concentrations of 0, 7.5, 15, 30, 60, or 120 ppm, 6 hours plus T90 (12 minutes) per day, 5 days per week for 12 exposures. All rats survived to the end of the studies. The final mean body weight of female rats exposed to 120 ppm and mean body weight gains of female rats exposed to 30 ppm or greater were significantly less than those of the chamber controls. Final mean body weights of exposed groups of male NBR rats and mean body weight gains of all exposed groups of male rats were significantly less than those of the chamber controls. Dark-stained urine was observed in all 120 ppm rats. Squinting, weeping, or matted fur around the eyes were noted in the majority of F344/N rats exposed to 120 ppm. The 2u-globulin concentrations in the kidney of male F344/N rats were significantly greater in all exposed groups than in the chamber control group. The absolute kidney weight of 60 ppm females and the relative kidney weights of male F344/N rats exposed to 30 ppm or greater and female rats exposed to 15 ppm or greater were significantly increased. The absolute liver weight of 120 ppm NBR male rats and the relative liver weights of male and female rats exposed to 60 or 120 ppm were significantly increased. In the nose, the incidences of mononuclear cell cellular infiltration were generally significantly increased in all exposed groups of rats, and incidences of olfactory epithelium degeneration and glandular hypertrophy occurred in all male F344/N rats exposed to 120 ppm. 2-WEEK STUDY IN MICE: Groups of five male and five female mice were exposed to tetralin at air concentrations of 0, 7.5, 15, 30, 60, or 120 ppm, 6 hours plus T90 (12 minutes) per day, 5 days per week for 13 exposures. All mice survived to the end of the study. Mean body weights of male and female mice were similar to those of the chamber controls. Dark-stained urine was observed in most of the exposed mice. The absolute and relative liver weights of 60 and 120 ppm males and 30 and 120 ppm females and the relative liver weights of 60 ppm females were significantly greater than those of the chamber controls. In the nose, the incidences of olfactory epithelium atrophy were significantly increased in 60 and 120 ppm males and females. Glandular dilatation occurred in all 120 ppm females, and glandular hyperplasia occurred in all 120 ppm males and females. 3-MONTH STUDY IN RATS: Groups of 10 male and 10 female rats were exposed to tetralin at air concentrations of 0, 7.5, 15, 30, 60, or 120 ppm, 6 hours plus T90 (12 minutes) per day, 5 days per week for 14 weeks. The same exposure concentrations were given to additional groups of 10 male and 10 female clinical pathology study rats for up to 6 weeks and five male renal toxicity rats for 2 weeks. All rats survived to the end of the study. During the first 4 weeks of exposure, dark-stained urine was observed in the catch pans of rats exposed to 30, 60, or 120 ppm. Tetralin induced a minimal decrease in the erythron in both sexes that resulted in a hematopoietic response. Tetralin increased urine aspartate aminotransferase and urine lactate dehydrogenase activities (males and females) and glucose/creatinine ratio (males), suggestive of renal injury. The absolute kidney weights of 60 and 120 ppm females and the relative kidney weights of males and females exposed to 15 ppm or greater were significantly greater than those of the chamber controls. Concentrations of 2u-globulin in the kidney of exposed male rats were generally greater than those of the chamber controls at all time points and greater at 6 and 14 weeks than at 2 weeks. There were significantly increased incidences of olfactory epithelium necrosis in rats exposed to 30 ppm or greater and of olfactory epithelium regeneration in 60 and 120 ppm rats. 3-MONTH STUDY IN MICE: Groups of 10 male and 10 female mice were exposed to tetralin at air concentrations of 0, 7.5, 15, 30, 60, or 120 ppm, 6 hours plus T90 (12 minutes) per day, 5 days per week for 14 weeks. All mice survived to the end of the study. Mean body weights of 120 ppm males were significantly less than those of the chamber controls. Dark-stained urine was observed in the catch pans of mice exposed to 30, 60, or 120 ppm during the first month of the study. Tetralin induced a minimal decrease in the erythron in both sexes that resulted in a hematopoietic response. The relative liver weights of 120 ppm males and 30 ppm or greater females were significantly greater than those of the chamber controls. Incidences of olfactory epithelium metaplasia in 60 and 120 ppm males and females, respiratory epithelium hyaline droplet accumulation in 120 ppm males and 60 and 120 ppm females, cytoplasmic eosinophilic granules within the transitional epithelium lining the urinary bladder in all exposed groups of males and females, and ovarian atrophy and uterine atrophy in 60 and 120 ppm females were significantly increased. 2-YEAR STUDY IN RATS: Groups of 50 male and 50 female rats were exposed to tetralin at air concentrations of 0, 30, 60, or 120 ppm, 6 hours plus T90 (12 minutes) per day, 5 days per week for 105 weeks. Additional groups of five male and five female rats were exposed to the same concentrations for 12 months. Survival of all exposed groups of rats was similar to that of the chamber controls. Mean body weights of 120 ppm females were 6% less than those of the chamber controls after week 29. Dark-stained urine was observed in all exposed groups of rats. Creatinine-adjusted levels of all urinary metabolites increased with increasing exposure concentration in males and females. In the standard evaluation of the kidney, there were slightly increased incidences of cortical renal tubule adenoma in male rats. In the combined analysis of single and step sections, the incidence of cortical renal tubule adenoma was significantly increased in the 120 ppm group. In the combined analysis, there was also a significantly increased incidence of renal tubule hyperplasia in the 120 ppm group. In 120 ppm males in the standard evaluation, the severity of chronic nephropathy was increased and the incidence of transitional epithelial hyperplasia in the renal pelvis was significantly increased. Three hepatocellular adenomas occurred in 120 ppm females, and one hepatocellular carcinoma each was observed in the 60 and 120 ppm groups. The incidences of uterine stromal polyp and endometrium hyperplasia were significantly increased in 120 ppm females. Incidences of interstitial cell adenoma and germinal epithelium atrophy of the testis in 30 and 120 ppm males were significantly greater than those in the chamber controls. The incidences of olfactory epithelium degeneration, metaplasia, basal cell hyperplasia, suppurative inflammation, and mineralization (except 30 ppm females) in the nose were significantly increased in all exposed groups of rats. The incidences of glandular dilatation were significantly increased in 120 ppm males and all exposed groups of females. The incidences of respiratory epithelium chronic inflammation were significantly increased in males exposed to 60 or 120 ppm and all exposed groups of females. The incidences of lens cataract in 120 ppm females were significantly increased. 2-YEAR STUDY IN MICE: Groups of 50 male and 50 female mice were exposed to tetralin at air concentrations of 0, 30, 60, or 120 ppm, 6 hours plus T90 (12 minutes) per day, 5 days per week for 105 weeks. Additional groups of five male and five female mice were exposed to the same concentrations for 12 months. Survival of 60 and 120 ppm female mice was significantly greater than that of the chamber controls. The mean body weights of all exposed groups of male and female mice were similar to those of the chamber controls by the end of the study. Dark-stained urine was observed in all exposed groups of male mice and in females exposed to 60 or 120 ppm. Creatinine-adjusted levels of all urinary metabolites increased with increasing exposure concentration in males and females. The incidence of hemangiosarcoma of the spleen was increased in 120 ppm females and exceeded the historical control range for inhalation studies. The incidences of olfactory epithelium atrophy, respiratory metaplasia, glandular hyperplasia, and suppurative inflammation in exposed groups of mice were significantly greater than those in the chamber controls. Transitional epithelium cytoplasmic eosinophilic granules were present in the urinary bladder of all exposed mice. (ABSTRACT TRUNCATED)
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PMID:Toxicology and carcinogenesis studies of tetralin (CAS No. 119-64-2) in F344/N rats and B6C3F1 mice (inhalation studies). 2168 56