A new mathematical equation has been developed by which whole-body exposure to gamma radiation may be used to predict the survival characteristic of the intestinal crypt in mice pretreated with N-nitrosodiethylamine (NDEA). A computer fitting procedure showed the best agreement between predicted and observed curves. The results suggest that fewer cells may survive in crypts after gamma irradiat...

We tested whether a concentration of unleaded gasoline (UG) vapor that was selectively hepatocarcinogenic in female mice in a chronic bioassay is antiestrogenic and whether liver tumor promotion by UG is secondary to antiestrogenicity. Twelve-day-old female C57BL/6 x C3H F1 mice (hereafter called B6C3F1) received i.p. injections of N-nitrosodiethylamine (5 mg/kg) or vehicle. Beginning at 5-7 we...

Naturally occurring plant products belonging to different chemical classes namely alizari n, an anthraquinone, caffeine, a methyl xanthine derivative and quercetin, a flavonol were studied for their effect on elimination of metabolites of [14C]_N_ nitrosodiethylamine e4C-NDEA) through respiration in mice. Treatment with caffeine, quercetin and alizarin at doses of 200, 9 and 9 JLg/ml respective...

To investigate the hypothesis that tumor promotion by chlorinated aromatic hydrocarbons involves Ah receptor occupation and subsequent induction of cytochromes P-450 1a-1, effects of Aroclor 1254 or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were examined in N-nitrosodiethylamine-initiated mice with different Ah receptor phenotype. Levels of cytochromes P-450 1a and 2b were measured by enzyme a...

Male F344/NCr rats, 6 wk old, were fed 500 ppm of phénobarbital (PB) or equimolar doses of either 5-ethyl-5-phenylhydantoin (EPH) or 5,5-diethylhydantoin (EEH) in diet for 2 wk and hepatic cytochrome P450-mediated alkoxyresorufm 0-dealkylase and aminopyrine A'-demethylase activities were determined. Both PB and EPH greatly increased P450-mediated enzyme activities in rat liver while EEH was in...

this study was designed to explore the protective effects of abrus precatorius l. (leguminosae) (ap) in hepg2 cells and n-nitrosodiethylamine (ndea) induced hepatocellular carcinoma in swiss albino rats. the effects of aqueous/ethanolic (50%) extract of ap on hepatic markers, haematological and histopathological parameters, and antioxidant enzymes were evaluated in ndea (200 mg/kg and ccl4, 3 m...

In vitro treatment of erythrocytes of normal and hypercholesterolemic rats with N-nitrosodiethylamine (NDEA), an important carcinogen frequently present in human environment and food chain resulted in a marginal increase in osmotic fragility of erythrocytes without affecting their antioxygenic potential as evidenced by insignificant effect on lipid peroxidation (LPO). However, (LPO) of all the ...