Effects of benzo[a]pyrene on tissue activities of metabolizing enzymes and antioxidant system in normal and protein-malnourished rats

The effects of benzoa]pyrene (Ba]P) on some drug-metabolizing and antioxidant systems in liver, lung, and stomach were investigated in normal and protein malnutrition (PM) rats. PM significantly inhibited tissue glutathione (GSH) content and increased hepatic lipid peroxidation. Cytochrome P450 isoform CYP1A1 was significantly increased in various tissues (42-73%). Also, lung glutathione S-transferase (GST) activity was significantly decreased (19%) in PM rats. On the other hand, Ba]P significantly induced tissue GSH of control and PM rats. Also, hepatic lipid peroxidation were significantly increased in control rats treated with Ba]P. Superoxide dismutase (SOD) activity was decreased by Ba]P treatment in PM rat stomach. Ba]P significantly induced both quinone reductase (QR) (in all tissues) and hepatic GST of control and PM rats. GST activity in PM rat liver was significantly higher than that of control rat liver after Ba]P treatment. Also, Ba]P induced hepatic CYP1A1 by 32-fold and 27-fold (P < or = 0.05) in control and PM rats, respectively. Stomach and hepatic UDP-glucuronosyltransferase activities were significantly decreased (34%) and increased (74%), respectively by Ba]P in PM rats. The results suggest that PM status has a modifying effect on the response of some antioxidant and metabolizing systems to a well-known carcinogen risk.