Effect of administration route of 3-methylcholanthrene on the inducibility of intestinal drug-metabolizing enzymes.
The inducibility of the mucosal drug-metabolizing enzymes of rat small intestine was studied by administering 3-methylcholanthrene either intragastrically or intraperitoneally. The aryl hydrocarbon hydroxylase activity was 4.1 times higher after intragastric than after intraperitoneal administration of methylcholanthrene. The ethoxycoumarin-O-diethylase activity was 11 times and UDP-glucuronosyltransferase (with p-nitrophenol as substrate) activity was 3 times higher after intragastric administration than after intraperitoneal administration. The epoxide hydratase activity was, on the other hand, 38% lower after intragastric administration of 3-methylcholanthrene than after intraperitoneal administration. The results suggest that compounds entering the body intragastrically, e.e. in the diet, might have profound enzyme-specific effects on the intestinal metabolic rates of drugs.
D015660:7-Alkoxycoumarin O-Dealkylase; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D001711:Biotransformation; D004750:Enteral Nutrition; D004789:Enzyme Activation / Q000187:drug effects*; D004851:Epoxide Hydrolases / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000378:metabolism; D007274:Injections, Intraperitoneal; D007421:Intestine, Small / Q000201:enzymology*; D008748:Methylcholanthrene / Q000008:administration & dosage* / Q000378:metabolism; D010105:Oxygenases / Q000378:metabolism; D051381:Rats
D008748:Methylcholanthrene; D010105:Oxygenases; D015660:7-Alkoxycoumarin O-Dealkylase; D001189:Aryl Hydrocarbon Hydroxylases; D014453:Glucuronosyltransferase; D004851:Epoxide Hydrolases