Abstract
Effect of zymosan, a typical reticuloendotherial stimulator, on hepatic drug-metabolizing enzymes was examined in mice. 1) When given in vivo, it depressed all the activities of aminopyrine N-demethylase, p-nitroanisole O-demethylase, and aniline hydroxylase. It was shown that the effect of zymosan on drug metabolism was exerted solely on microsomes and there was a marked decrease of cytochrome P-450 content in microsomes of zymosan-treated animals. 2) Aminopyrine N-demethylase activity was found to become minimum 24 hours after the administration of zymosan. On the other hand, phagocytic activity was enhanced at the same time when the maximum depression of the metabolism of aminopyrine was observed.
