title: Microsomal metabolism of pyrrolizidine alkaloids: N-oxidation of seneciphylline and senecionine.
abstract: In vivo pretreatment of rats with phenobarbital or beta-naphthoflavone reduced the specific activity of microsomal pyrrolizidine alkaloid N-oxide formation. Heat pretreatment of microsomes under conditions intended to selectively inactivate the flavin-containing monooxygenase did not lower the rate of N-oxidation. Incubation in the presence of cytochrome P-450 inhibitors diminished the microsomal formation of N-oxide. The observations are consistent with the hypothesis that pyrrolizidine alkaloid N-oxidation
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004790:Enzyme Induction / Q000187:drug effects; D006358:Hot Temperature; D066298:In Vitro Techniques; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism*; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000378:metabolism; D011763:Pyrrolizidine Alkaloids / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D011763:Pyrrolizidine Alkaloids; C013678:seneciphylline; C009237:senecionine; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming)