title: Metabolism of 2-aminofluorene by rat small-intestine fractions: differential effect of intragastric versus intraperitoneal administration of 3-methylcholanthrene.
abstract: The influence of 3-methylcholanthrene (3-MC) induction on small intestinal enzymes was studied by measuring the enzymatic characteristics of 2-aminofluorene N-hydroxylase and the activation of this aromatic amine into mutagen(s) towards Salmonella typhimurium. When injected intraperitoneally to rats, 3-MC modified neither the N-hydroxylation nor the mutagenic properties of 2-aminofluorene (2-AF) in the presence of postmitochondrial and microsomal fractions from small intestine. On the other hand, the intragastric administration of the inducer slightly increased affinity and significantly induced maximum velocity of N-hydroxylase. Moreover, the ability of the small intestinal fractions to activate 2-AF into mutagenic intermediate(s) was enhanced after intragastric application. The mode of administration seems to be crucial in the induction of small intestinal enzymes required for metabolic and mutagenic activation of carcinogenic aromatic amines such as 2-AF.
mesh_terms: D000818:Animals; D001711:Biotransformation / Q000187:drug effects; D002849:Chromatography, Gas; D004790:Enzyme Induction / Q000187:drug effects; D007274:Injections, Intraperitoneal; D007421:Intestine, Small / Q000201:enzymology / Q000378:metabolism*; D007441:Intubation, Gastrointestinal; D008297:Male; D008748:Methylcholanthrene / Q000008:administration & dosage / Q000494:pharmacology*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D009152:Mutagenicity Tests; D051381:Rats; D011919:Rats, Inbred Strains; D012486:Salmonella typhimurium / Q000235:genetics
chemical_list: D008748:Methylcholanthrene; D006899:Mixed Function Oxygenases; C035198:arylamine N-hydroxylase