title: Liver microsomal cytochromes P-450 and azoreductase activity.
abstract: Hepatic microsomal azoreductase activity with amaranth (3-hydroxy-4[(4-sulfo-1-naphthalenyl)azo]-2,7-naphthalenedisulfonic acid trisodium salt) as a substrate is proportional to the levels of microsomal cytochrome P-450 from control or phenobarbital-pretreated rats and mice or cytochrome P-448 from 3-methylchol-anthrene-pretreated animals. In the "inducible" C57B/6J strain of mice, 3-methylcholanthrene and phenobarbital pretreatment cause an increase in cytochrome P-448 and P-450 levels, respectively, which is directly proportional to the increase of azoreductase activity. However, in the "noninducible" DBA/2J strain of mice, only phenobarbital treatment causes the increase both in cytochrome P-450 levels and azoreductase activity, while 3-methylcholanthrene has no effect. These experiments suggest that the P-450 type cytochromes are responsible for azoreductase activity in liver microsomes.
mesh_terms: D000548:Amaranth Dye / Q000378:metabolism; D000818:Animals; D001391:Azo Compounds / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D003580:Cytochromes / Q000378:metabolism; D004790:Enzyme Induction; D008748:Methylcholanthrene / Q000494:pharmacology; D051379:Mice; D008862:Microsomes, Liver / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D010634:Phenobarbital / Q000494:pharmacology; D051381:Rats; D004124:p-Dimethylaminoazobenzene
chemical_list: D001391:Azo Compounds; D003580:Cytochromes; D008748:Methylcholanthrene; D003577:Cytochrome P-450 Enzyme System; D000548:Amaranth Dye; D004124:p-Dimethylaminoazobenzene; D006899:Mixed Function Oxygenases; D009247:NADH, NADPH Oxidoreductases; D010634:Phenobarbital