title: The effects of fractionated thermally oxidized corn oil on drug-metabolizing enzyme systems in the rat.
abstract: Corn oil samples were heated, with aeration, to 210 degrees C for a total of 5 hr. Both fresh and oxidized samples were urea-fractionated and the individual fractions were administered to male Sprague-Dawley rats by gastric intubation. The effects of urea adducts, adduct-free fractions, non-saponifiable fractions and unfractioned fresh and thermally oxidized oil samples on hepatic, intestinal and colonic drug-metabolizing enzymes were determined. The treatments had no significant effects on hepatic or intestinal drug-metabolizing or mixed-function oxidase activities. There was a significant (P less than 0.05) increase in colonic UDP-glucuronyltransferase activity in rats treated with thermally oxidized corn oil, while the non-saponifiable fraction of the same sample decreased (P less than 0.1) the activity of this enzyme. There was also a significant increase in the activity of colonic benzo[a]pyrene hydroxylase in rats treated with the non-adduct fraction or with urea adducts of the thermally oxidized corn oil. These data suggest the colon as a possible specific site for the alteration of mixed-function oxidase activities by products of thermally oxidized oils.
mesh_terms: D000818:Animals; D001579:Benzopyrene Hydroxylase / Q000032:analysis; D002273:Carcinogens / Q000378:metabolism; D003106:Colon / Q000201:enzymology; D003314:Corn Oil; D014453:Glucuronosyltransferase / Q000032:analysis; D006358:Hot Temperature; D007421:Intestine, Small / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D008297:Male; D009821:Oils / Q000494:pharmacology*; D010084:Oxidation-Reduction; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D002273:Carcinogens; D009821:Oils; D004364:Pharmaceutical Preparations; D003314:Corn Oil; D001579:Benzopyrene Hydroxylase; D014453:Glucuronosyltransferase