Pituitary regulation of sex-specific forms of cytochrome P-450 in liver microsomes of rats.

Effects of hypophysectomy and treatment with testosterone or estradiol on the sex-specific forms of cytochrome P-450, P-450-male and P-450-female, were examined. The amounts of P-450-male as well as drug oxidation activities were decreased by hypophysectomy of male rats. In female rats, drug oxidation activities were increased by hypophysectomy, which was associated with the disappearance of P-450-female and the appearance of P-450-male. Treatment of hypophysectomized female rats with testosterone or estrodiol effected minor changes in the amounts of P-450-male.