DIETARY LIPIDS INDUCE PHASE 2 ENZYMES IN RAT SMALL-INTESTINE

We examined the role of dietary lipids in determining the activities o f glutathione S-transferase (GST) and UDPglucuronosyltransferase (UGT) in rat small intestine. Male Wistar rats were fed a fat-free (FF) die t or isocaloric control diet containing 5% corn oil (CO) or 5% fish oi l (FO) for 3 weeks. The activities of these enzymes were about 2-fold higher in rats fed the FO diet vs. the FF diet. Intermediate levels of enzyme activity were found in rats fed the CO diet. Diet-induced diff erences in enzyme levels were shown by immunoblotting. The highest lev els of glutathione S-transferase and UDPglucuronosyltransferase were d etected in rats fed the FO diet. The lowest levels of these enzymes we re found in rats fed the FF diet. Intermediate levels of enzyme were d etected in rats fed the CO diet. Thus, diet-induced differences in enz yme activities were paralleled by changes in enzyme levels. Fatty acid analysis of mucosal lipids showed that the FF and FO diets were assoc iated with decreased levels of linoleic and arachidonic acids as compa red with the CO diet.