Species and sex differences in the inhibitory action of the corticosteroid alclometasone dipropionate on the hepatic drug-metabolizing system

The effect of successive administration of the corticosteroid alclometasone dipropionate (ACM) on the hepatic drug-metabolizing system was examined using male and female rats. Although some pharmacological changes such as increases in plasma Enzyme activity, lipid level and protein concentration appeared similarly in ACM-treated male and female rats, the activities of 7-alkoxycoumarin O-dealkylase, especially the O-depropylation activity, decreased dose-dependently by ACM administration only in male rats. ACM did not affect the hepatic drug-metabolizing activity in female rats and mice of both sexes. Also, ACM did not inhibit androgen-independent aniline hydroxylase activity even in male rats. The time course of changes of the drug-metabolizing system in male rats showed a rapid decrease in cytochrome P-450 content and O-depropylation activity following successive treatments with ACM, but there was a slow onset in the decreases of the O-demethylation and O-deethylation activities of 7-alkoxycoumarin. When ACM was withdrawn, the O-demethylation and O-deethylation activities rapidly returned to their control levels, while recovery of the O-depropylation activity was slow. These results suggested that ACM inhibits the hepatic drug-metabolizing Enzyme activity associated with a specific form(s) of androgen-dependent cytochrome P-450 in male rats.