Steroid secretion by the adrenal gland of foetal and neonatal sheep

From the left adrenal of ten sheep foetuses and four lambs aged from 110 days after conception to 14 days after birth, adrenal venous blood was collected and assayed for cortisol, corticosterone and aldosterone. These steroids were secreted at all ages but the rate of secretion was greatly in-creased toward term and afterbirth. The increase coincidedwith morphological changes in the adrenal gland. At no stage was the rate significantly increased by corticotrophin, and in two young foetuses it was not decreased by dexamethasone. In two foetuses and one lamb, angiotensin II did not in-crease the rate of secretion of any of the three steroids significantly, and the blood pressure was raised only in the lamb. It is probable that the secretion of the steroids was maximal under the conditions of the experiments