Effects of dexamethasone on the hepatic cytochrome P450IIIA subfamily in two hamster strains Mesocricetus auratus and Cricetus griseus.

1. Administration of dexamethasone significantly reduced the amount of hepatic cytochrome P450 in Syrian golden and Chinese hamsters, while it increased the amount in rats. 2. In contrast to rats, the induction rate of the activities of erythromycin and troleandomycin N-demethylases by dexamethasone was relatively low, while that of the testosterone 6 beta-hydroxylase was high in the two hamster strains. 3. Western blot analysis revealed that dexamethasone did not modify markedly the pattern of the P450IIIA subfamily proteins in the two hamster strains.