Interaction of Testosterone and ACTH in the Regulation of Adrenal Corticosterone Secretion in the Male Rat

Testosterone administration to hypophysectomized male rats increased adrenal corticosterone secretion both in vitro and in vivo. Total steroid (blue tetrazolium + ) production was unaffected. Adrenal 5α-reductase activity was inhibited by testosterone. ACTH stimulated corticosterone and total steroid output and lowered reductase activity. Testosterone, when given in conjunction with ACTH, potentiated the effects of ACTH on corticosterone secretion and reductase activity but not on total steroid production. The data indicate that testosterone and ACTH can interact to stimulate corticosterone secretion in the rat. Adrenal 5α-reductase seems to be the common site of action for these effects. (Endocrinology91: 1247, 1972)