title: Effects of phenobarbital and methylcholanthrene on hepatic mixed-function-oxidase activities in hamsters.
abstract: The effects of the inducers phenobarbital (PB) and 3-methylcholanthrene (MC) on hamster liver mixed-function-oxidase activities were studied. Both inducers increased to content of cytochrome P-450 in the microsomes, aminopyrine demethylase activity, and biphenyl 4-hydroxylase activity when given for 8 days. The ability of liver homogenates from treated animals to activate compounds to mutagens was tested using the Salmonella/microsome test. Neither inducer appreciably altered mutagenicity of 2-acetylaminofluorene, benzidine, benzo(a)pyrene, aflatoxin B1, or sterigmatocystin. Mutagenicity of MC was increased when homogenates from MC-treated hamsters were used as a source of activating enzymes, and this mutagenicity could be correlated with increased biphenyl 2-hydroxylase activity.
mesh_terms: D000818:Animals; D006224:Cricetinae; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008647:Mesocricetus; D008748:Methylcholanthrene / Q000494:pharmacology*; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D009153:Mutagens / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism*; D010634:Phenobarbital / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D009153:Mutagens; D008748:Methylcholanthrene; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; D010634:Phenobarbital