摘要:The inhibitory effects of ozagrel (OZA), an imidazole derivative and a specific thromboxane synthase inhibitor, on a monooxygenase system in mouse hepatic microsomes were studied. Pentobarbital sleeping time was significantly prolonged by i.p. administration of a single dose of 100mg/kg of OZA, and the potency of OZA for the prolongation of sleeping time was similar to that of cimetidine. In vitro, OZA inhibited aminopyrine N-demethylase, aniline hydroxylase and testosterone 6β-and 7α-hydroxylase activities in hepatic microsomes with inhibition constants (Ki) of 0.19-3.72mM. The potency and the mode of inhibition of OZA for these enzyme activities were similar to those of cimetidine, while no inhibitory effect of OZA on testosterone 16α-hydroxylase activity was found. A spectrophotometric study revealed that the imidazole moiety of OZA binds to cytochrome P-450 and has little effect on reduced nicotinamide adenine dinucleotide phosphate cytochrome c reductase activity. These results indicated that OZA is an inhibitor of some cytochrome P-450-mediated drug metabolism in hepatic microsomes.