Record Display for the EPA National Library Catalog


OLS Field Name OLS Field Data
Main Title Tumor Promotion in Rat Liver.
Author Herren, S. L. ; Pereira, M. A. ;
CORP Author Health Effects Research Lab., Cincinnati, OH.
Year Published 1983
Report Number EPA/600/J-83/237;
Stock Number PB84-245646
Additional Subjects Phenobarbital ; Toxicology ; Bioassay ; Rats ; Liver ; Barbiturates ; Reprints ; Carcinogenesis
Library Call Number Additional Info Location Last
NTIS  PB84-245646 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 06/23/1988
Collation 9p
An initiation promotion bioassay for chemical carcinogens and tumor promoters has been developed in rat liver using presumed preneoplastic lesions, foci of gamma-glutamyltranspeptidase (GGTase)-positive hepatocytes, as the endpoint. To evaluate the tumor-promoting activity of phenobarbital, rats were administered diethylnitrosamine (DENA), 2.0 mmole/kg, followed by 500 ppm phenobarbital in their drinking water. After 6 weeks of phenobarbital promotion, the rats, had an increased incidence of foci as compared to nonphenobarbital-treated rats. By 50 weeks, the number of foci in the nonpromoted animals equaled the number observed with promotion. The stability and progression of GGTase-positive foci was determined in rats that received a 2/3 partial hepatectomy, followed 24 hours later by DENA administration (0.3 mmole/kg). The rats then received 500 ppm phenobarbital in the drinking water for 7 weeks. After 7 weeks, half of the rats were continued on phenobarbital and the other half were removed from phenobarbital treatment.