Dietary selenium, hepatic arylhydrocarbon hydroxylase and mutagenic activation of benzo(a)pyrene, 2-aminoanthracene and 2-aminofluorene

Abstract

The effect of dietary selenium (Se) on the hepatic aryl hydrocarbon hydroxylase (AHH) and mutagenic activation potential in young and adult rats was investigated. Animals were maintained on a low Se basal diet with or without 1 or 2 ppm Se supplementation (as sodium selenite) for 5 or 20 weeks. AHH inducibility was determined by an intraperitoneal injection of Aroclor 5 days prior to killing. A significant reduction in the AHH level was observed in the low Se group of young untreated rats only. Dietary Se did not affect AHH inducibility by Aroclor treatment and the induced AHH levels were similar in both dietary groups. 5 weeks on low dietary Se did not alter the AHH levels in untreated or treated adult rats. The levels of Se-dependent glutathione peroxidase (GSH-P) were decreased more drastically in the young than adult rats by low dietary Se. Studies on the metabolic activation potential of liver enzymes from young rats on basal and Se-supplemented diets showed that dietary Se did not alter the activation of benzo(a)pyrene (BP) to mutagens although differences in the activation of 2-aminofluorene (2AF) and 2-aminoanthracene (2AA) were observed.