Effects of dietary benzo(a) pyrene on intestinal phase I and phase II drug metabolizing systems in normal and vitamin A-deficient rats.
Feeding of vitamin A-deficient diet to male weanling rats for 10 weeks caused significant increase in the activities of Phase I enzyme system, i.e., cytochrome P-450, cytochrome b5 and arylhydrocarbon hydroxylase in the proximal, middle and distal segments of the intestine. Of the Phase II enzymes studied, UDP-glucuronyltransferase showed significant decrease whereas glutathione S-transferase showed significant increase. Treatment with benzo(a)pyrene caused greater induction in the levels of Phase I enzymes in deficient animals as compared to controls. In contrast to this, benzo(a)pyrene treatment induced the level of UDP-glucuronyltransferase in control rats more than in deficient rats. Intestinal NADPH cytochrome C-reductase and glutathione S-transferase remained insensitive to benzo(a)pyrene induction.
Gupta
P H
PH
Department of Gastroenterology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Mehta
S
S
Mehta
S K
SK
D000818:Animals; D001564:Benzo(a)pyrene / Q000008:administration & dosage / Q000494:pharmacology*; D001711:Biotransformation; D004435:Eating; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000187:drug effects / Q000201:enzymology; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D010088:Oxidoreductases / Q000378:metabolism*; D051381:Rats; D014802:Vitamin A Deficiency / Q000378:metabolism*; D015262:Xenobiotics / Q000493:pharmacokinetics
D015262:Xenobiotics; D001564:Benzo(a)pyrene; D010088:Oxidoreductases