Adrenal 5  -Reductase Activity in the Rat: Effects of Gonadectomy: Some Cofactor and Substrate Requirements

Abstract

Steroid 5α-reductase activity is demonstrated in the adrenal cortex of male and female rats (F > M). Following either orchiectomy or ovariectomy, activity of the enzyme is elevated extending previous findings of increased adrenal 5a-metabolite formation in gonadectomized rats. Reductase activity in adrenal tissue from castrate males is greater than that from castrate females. NADH enhances enzyme activity in whole homogenates. Centrifugation studies demonstrate most of the activity to reside in the 105,000g sediment. Compared to corticosterone, testosterone is a more preferred substrate, whereas Cortisol is less well metabolized and aldosterone least of all.