N-Hydroxylation of phenacetin by hamster liver microsomes

Hamster liver microsomes have been shown to catalyze the N-hydroxylation of phenacetin. The reaction, which requires oxygen and NADPH, is inhibited by a carbon monoxide/oxygen atmosphere, indicating that it is catalyzed by a cytochrome P-450-dependent mixed-function oxidase. The N-hydroxyphenacetin can be further metabolized by the microsomes, and the reaction is inhibited by phenacetin.