{"title":"Three-generation reproduction study of rats ingesting 2,4,5-trichlorophenoxyacetic acid in the diet","authors":"F.A. Smith, F.J. Murray, J.A. John, K.D. Nitschke, R.J. Kociba, B.A. Schwetz","doi":"10.1016/0015-6264(81)90301-1","DOIUrl":null,"url":null,"abstract":"<div><p>Male and female 4–6-wk-old Sprague-Dawley rats (F<sub>0</sub>) were fed lab chow containing 2,4,5-T to provide dosage levels of 0, 3, 10 or 30 mg/kg/day for 90 days and were then bred. At day 21 of lactation, pups were randomly selected for the following generation (F<sub>1</sub>) and the rest were autopsied. Subsequent matings were conducted to produce F<sub>2</sub>, F<sub>3a</sub> and F<sub>3b</sub> litters, successive generations being fed from weaning on the appropriate test or control diet. Fertility was decreased in the matings for the F<sub>3b</sub> litters in the group on the 10-mg/kg/day dose level. Postnatal survival was significantly decreased in the F<sub>2</sub> litters of the 10-mg/kg group and the F<sub>1′</sub> F<sub>2</sub> and F<sub>3a</sub> litters of the 30-mg/kg/day group. The relative liver weight of weanlings was significantly increased in the F<sub>2′</sub> F<sub>3a</sub> and F<sub>b</sub> litters of the 30-mg/kg/day group. A significant decrease in relative thymus weight was seen only in the F<sub>b</sub> generation of this dosage group. Thus, dose levels of 2,4,5-T that were sufficiently high to cause signs of toxicity in neonates had no effect on the reproductive capacity of rats, except for a tendency toward a reduction in postnatal survival at a dose level of 30 mg/kg/day. Reproduction was not impaired at the lowest dose level (3 mg/kg/day).</p></div>","PeriodicalId":12197,"journal":{"name":"Food and cosmetics toxicology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1981-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0015-6264(81)90301-1","citationCount":"9","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Food and cosmetics toxicology","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/0015626481903011","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 9
Abstract
Male and female 4–6-wk-old Sprague-Dawley rats (F0) were fed lab chow containing 2,4,5-T to provide dosage levels of 0, 3, 10 or 30 mg/kg/day for 90 days and were then bred. At day 21 of lactation, pups were randomly selected for the following generation (F1) and the rest were autopsied. Subsequent matings were conducted to produce F2, F3a and F3b litters, successive generations being fed from weaning on the appropriate test or control diet. Fertility was decreased in the matings for the F3b litters in the group on the 10-mg/kg/day dose level. Postnatal survival was significantly decreased in the F2 litters of the 10-mg/kg group and the F1′ F2 and F3a litters of the 30-mg/kg/day group. The relative liver weight of weanlings was significantly increased in the F2′ F3a and Fb litters of the 30-mg/kg/day group. A significant decrease in relative thymus weight was seen only in the Fb generation of this dosage group. Thus, dose levels of 2,4,5-T that were sufficiently high to cause signs of toxicity in neonates had no effect on the reproductive capacity of rats, except for a tendency toward a reduction in postnatal survival at a dose level of 30 mg/kg/day. Reproduction was not impaired at the lowest dose level (3 mg/kg/day).