title: The modulation by arylamines of the in vitro formation of superoxide anion radicals and hydrogen peroxide by rat liver microsomes.
abstract: A concentration-dependent increase in the generation of the superoxide anion radical (O-2), was observed during the incubation of benzidine (0.1-5 mM), but not of the structurally related compounds 4-aminobiphenyl, 2-aminobiphenyl or 4-fluoro-4'-aminobiphenyl, with NADPH-supplemented rat liver microsomes. This increase was partially inhibited by carbon monoxide and catalase but unaffected by 4-aminobiphenyl, a substrate of the cytochrome P-450 system. Microsomes from benzo(a)pyrene-treated, but not microsomes from phenobarbitone-pretreated rats, were responsible for a larger benzidine-dependent effect compared to microsomes from control animals. In contrast to the above observations, benzidine decreased the formation of hydrogen peroxide by NADPH-supplemented microsomal preparations from untreated rats. These results indicate that free radicals of oxygen are generated during the metabolism of some arylamines.
authors.forename: M
authors.initials: M
authors.lastname: Manno
authors.forename: C
authors.initials: C
authors.lastname: Ioannides
authors.forename: G G
authors.initials: GG
authors.lastname: Gibson
mesh_terms: D000588:Amines / Q000494:pharmacology*; D000611:Aminobiphenyl Compounds / Q000494:pharmacology; D000818:Animals; D001386:Azides / Q000494:pharmacology; D001560:Benzidines / Q000494:pharmacology; D002248:Carbon Monoxide / Q000494:pharmacology; D002273:Carcinogens / Q000494:pharmacology*; D002374:Catalase / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005609:Free Radicals; D006861:Hydrogen Peroxide / Q000096:biosynthesis*; D066298:In Vitro Techniques; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000378:metabolism; D009249:NADP / Q000494:pharmacology; D010084:Oxidation-Reduction / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D019810:Sodium Azide; D013481:Superoxides / Q000096:biosynthesis*
chemical_list: D000588:Amines; D000611:Aminobiphenyl Compounds; D001386:Azides; D001560:Benzidines; D002273:Carcinogens; D005609:Free Radicals; D013481:Superoxides; C006757:4-biphenylamine; C029876:benzidine; D009249:NADP; D002248:Carbon Monoxide; D003577:Cytochrome P-450 Enzyme System; D019810:Sodium Azide; D006861:Hydrogen Peroxide; D006899:Mixed Function Oxygenases; D002374:Catalase