Ntp Technical Report On The Toxicology And Carcinogenesis Studies Of 24 Dichlorophenol Cas No 120 83 2 In F334 N Rats And B6c3f1 Mice

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Download or read book NTP Technical Report on the Toxicology and Carcinogenesis Studies of Sodium Tungstate Dihydrate (CASRN 10213-10-2) in Sprague Dawley (Hsd:Sprague Dawley(r) SD(r)) Rats and B6C3F1/N Mice (Drinking Water Studies) written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: PERINATAL AND THREE-MONTH STUDY IN RATS: Beginning on GD\s6, groups of eight F0\stime-mated female rats were exposed to ST in drinking water throughout gestation and lactation at one of five exposure concentrations (125, 250, 500, 1,000, or 2,000\smg/L) or were provided the vehicle control (deionized water). Groups of 10 F1\srats per sex continued on in the study after weaning and were given drinking water containing the same respective ST concentrations for 3\smonths. There were no significant effects of ST exposure on pregnancy status, maternal survival, or littering parameters. By the end of lactation, dams in the 1,000 and 2,000\smg/L groups showed significant decreases in group mean body weight of approximately 10% and 18%, respectively, and water consumption was significantly decreased for the 500, 1,000, and 2,000\smg/L groups relative to the vehicle control group over the LD\s17 to LD\s21 interval. When adjusted for litter size, the mean body weight of male and female pups in the 2,000\smg/L group on PND\s21 was significantly decreased by approximately 16% and 11%, respectively, compared to the corresponding vehicle control groups. There were no early deaths during the 3-month study. When compared to the vehicle control group, final mean body weights were lower for the 1,000 and 2,000\smg/L males and 2,000 mg/L females. Water consumption was lower for the 1,000 and 2,000\smg/L males and females. The urine xanthine/creatinine ratios were significantly increased in all male and female exposed groups. Serum insulin concentrations were significantly decreased in the 2,000\smg/L males relative to the vehicle control males. Significantly decreased absolute weights were observed in several organs but were considered secondary to body weights reductions. Exposure-related histological lesions were limited to the kidneys and included increased incidences of renal tubule regeneration in the 1,000 and 2,000\smg/L males and females; the increases in the 2,000\smg/L groups were significant relative to the vehicle control group. CONCLUSIONS: Under the conditions of these 2-year drinking water studies, there was no evidence of carcinogenic activity of sodium tungstate dihydrate (ST) in male Hsd:Sprague Dawley(r) SD(r) rats at exposure concentrations of 250, 500, or 1,000\smg/L. There was equivocal evidence of carcinogenic activity of ST in female Hsd:Sprague Dawley(r) SD(r) rats based on increased incidences of C-cell adenoma or carcinoma (combined) of the thyroid gland. There was equivocal evidence of carcinogenic activity of ST in male B6C3F1/N mice based on the occurrences of renal tubule adenoma or carcinoma (combined) in exposed animals. There was no evidence of carcinogenic activity of ST in female B6C3F1/N mice at exposure concentrations of 500, 1,000, or 2,000\smg/L. Exposure to ST in drinking water caused increased incidences of nonneoplastic lesions in the kidney of male and female rats and mice, in the uterus of female rats, in the large intestine of male and female mice, and in the testes of male mice.SYNONYMS: Tungstic acid sodium salt dehydrate.