title: Inhibition of rat liver cytochrome P-450 by benzyl hydrodisulfide.
abstract: The inhibition of rat liver microsomal cytochrome P-450 by benzyl hydrodisulfide has been examined as a model system for the inactivation of cytochrome P-450 seen during the microsomal metabolism of thiono-sulfur-containing compounds. Benzyl hydrodisulfide decreased enzymatic activity toward benzphetamine when incubated with hepatic microsomes prior to the assay for monooxygenase activity. In addition, incubation of microsomes with the hydrodisulfide caused a decrease in the level of cytochrome P-450 detectable as its carbon monoxide complex as well as a decrease in heme detectable as its pyridine-hemochromogen. In a typical experiment, the loss of enzymatic activity, cytochrome P-450, and heme were 65, 56, and 51%, respectively. These data suggest that the major loss of monooxygenase activity and of cytochrome P-450 which was seen on incubation of microsomes with benzyl hydrodisulfide results from an alteration in the structure of the heme moiety of cytochrome P-450. A similar alteration in the heme moiety of cytochrome P-450 is believed to be responsible, in part, for the loss of monooxygenase activity and cytochrome P-450 seen on incubation of parathion and other thiono-sulfur-containing compounds with hepatic microsomes or a reconstituted cytochrome P-450-containing monooxygenase system.
mesh_terms: D000818:Animals; D065607:Cytochrome P-450 Enzyme Inhibitors; D003573:Cytochrome b Group; D003580:Cytochromes / Q000378:metabolism; D004220:Disulfides / Q000494:pharmacology*; D006418:Heme / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000037:antagonists & inhibitors*; D010088:Oxidoreductases / Q000037:antagonists & inhibitors*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D003573:Cytochrome b Group; D003580:Cytochromes; D004220:Disulfides; C034956:benzyl hydrodisulfide; D006418:Heme; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases