Nakayama H, Fujihara S, Nakashima T, Kurogochi Y
Department of Pharmacology, Nara Medical University, Japan.
Biochem Pharmacol. 1987 Dec 15;36(24):4313-7. doi: 10.1016/0006-2952(87)90677-0.
Using antibody against NADPH-cytochrome P-450 reductase and several effectors of cytochrome P-450 and FAD-containing monooxygenase, we investigated nicotine metabolites formed by these two enzymes. When [3H]nicotine was metabolized by the combination of liver microsomes of guinea pigs and partially purified aldehyde oxidase, three distinct spots corresponding to nicotine, cotinine and nicotine-1'-oxide were observed on fluorograms of thin-layer chromatography. Antibody against NADPH-cytochrome P-450 reductase inhibited the formation of cotinine but not nicotine-1'-oxide. Metyrapone and n-octylamine inhibited the cotinine formation, while methimazole prevented the formation of nicotine-1'-oxide. These results show that microsomal electron transport systems participate in the formation of nicotine-1'-oxide and strongly suggest the involvement of FAD-containing monooxygenase in the formation of nicotine-1'-oxide.
