Influence of 13-cis retinoic acid and of arotinoid on the cytochrome P-450 system in rat liver.

Female Wistar rats were treated with either 13-cis retinoic acid or arotinoidethyl ester in a dose comparable to those used in humans over different periods up to 28 days. In the liver of the animals the following parameters were estimated: microsomal protein content, cytochrome P-450 content, and cytochrome P-450-dependent activities of enzymes such as aminopyrine-N-demethylase, arylhydrocarbon hydroxylase, and 7-ethoxycoumarin deethylase. Only a transitory increase of the aminopyrine-N-demethylase after 3 days of treatment could be demonstrated. From this animal study, there is no evidence of interactions between retinoids and drug-metabolizing monooxygenases, e.g., the metabolism of contraceptive active steroids.