Adrenal Steroid Secretion in Rabbits Following Prolonged ACTH Administration

Abstract

Summary Porcine ACTH was administered to rabbits for periods of 15 and 30 days. At the end of this time the quantity of corticosterone isolated from adrenal venous blood was significantly reduced, while the secretion of cortisol tripled. This resulted in a drop in the corticosterone/cortisol ratio from a control value of 20:1 towards unity. The hypertrophied adrenals of the ACTH treated rabbits secreted the same quantity of steroids per unit time as the control animals. A possible explanation of these changes is discussed. We wish to thank Miss Jannas Rice for valuable technical assistance.