Modulation of the uptake and retention of estradiol-17beta in the ovine corpus luteum by luteinizing hormone.

The uptake and retention of 3H-estradiol by the ovine corpus luteum (induced by superovulation) was maximal through days 8-12 of the cycle with little or no uptake and retention during luteinization or regression. LH, but not FSH or prolactin, inhibited the uptake and retention of estradiol via stimulation of progesterone synthesis.

Role of adrenal 5alpha-reductase activity in determining the responsiveness of hypophysectomized rats to ACTH.

Studies were conducted to examine the contribution of adrenal 5alpha-reductase to the phenomenon of diminished adrenal "responsiveness" to ACTH after hypophysectomy in rats. Rats hypophysectomized for 1 week secreted small amounts of corticosterone (B), 5alpha-dihydrocorticosterone (DHB) and 3beta,5alpha-tetrahydrocorticosterone (R) acutely after ACTH. Adrenal reductase activity in vitro at that time was high.