Induction of the hepatic cytochrome P-450 dependent monooxygenase system by cis- and trans-5,10-dihydrogen mirex

The hepatic induction of cytochrome P-450-dependent monooxygenase components by cis- and trans-5,10-dihydrogen mirex was studied in male and female laboratory rats. There were sex-dependent differences between the two isomeric derivatives of mirex. The cis-isomer significantly increased aniline hydroxylase activity in the female, but not in the male. In contrast, aminopyrine N-demethylase was significantly increased by the cis-isomer in both sexes. The trans-isomer increased the hydroxylase and N-demethylase activities in both sexes. The cis-isomer induced NADPH-cytochrome c reductase in the female, and the trans-isomer did not. Both isomers induced hepatic reductase activity in the male rat. No sex-dependent differences in the hepatic induction of cytochrome P-450 were observed for either isomer.