STEROIDOGENIC PROPERTIES OF PURIFIED CORTICOTROPINS¹

Abstract

δ1 and β corticotropins, prepared by Bell and co-workers, were assayed for hydrocortisone and aldosterone stimulating activity in the decerebrate dog. The two preparations were foundto be of approximately equal potency in stimulating hydrocortisone secretion. However, δ1 corticotropin proved to be several times as active as β corticotropin in stimulating the secretion of aldosterone. The aldosterone stimulating activity of δ1 corticotropin is destroyed by heating in alkali, indicating that it is not due to the melanocyte stimulating activity known to be present in this preparation. NUMEROUS, frequently conflicting, reports of the aldosterone stimulating activity of ACTH have appeared in the literature. In the hypophysectomized dog a modest increase in the rate of secretion ofthe steroid has been reported to follow the infusion of ACTH. The increase was small when compared to the effect of ACTH on the secretion of the other corticosteroids.