MICROSOMAL-ENZYME ACTIVITY, GLUTATHIONE-S-TRANSFERASE PLACENTAL FORM EXPRESSION, CELL-PROLIFERATION, AND VITAMIN-A STORES IN LIVERS OF RATSCONSUMING GREAT-LAKES SALMON

Male and female Sprague-Dawley rats were fed diets incorporating lyoph ilized chinook salmon obtained from Lake Ontario and Lake Huron. After 70 days, females were bred and the progeny (F-1) were reared on the s ame fish-based diets as the adults (F-0). After 78-133 days on the die ts, males and females of both generations were sacrificed and hepatic microsomal enzyme activities determined, along with glutathione S-tran sferase-placental form (GSTP) expression and hepatic cellular prolifer ation. Hepatic P450 enzyme activities (MROD, EROD, PROD, BROD, and ami nopyrine) were increased significantly by fish diets from both sources . Increases in hepatic enzyme activity were greatest for fish caught f rom Lake Ontario and reflected the total levels of organochlorine cont aminants in the fish. GSTP and cell proliferation rates did not show a ng diet-related or dose-related changes. Vitamin A stores were analyze d as the concentration of liver retinyl palmitate. In rats receiving t he highest TEQ dose (i.e., 20% Lake Ontario fish diet), vitamin A stor es were significantly lower in F-0 adults, F-1 weanlings, and F-1 adul t females. (C) 1998 Academic Press.