Effects of ACTH, Cortisone and Hydrocortisone on Renal Functions of Hypophysectomized Dogs

Abstract

Attempts were made to restore or replace the deficient adrenocortical functions of hypophysectomized dogs (56 - 496 days post-hypophysectomy) by(a) stimulation of the atrophic adrenal cortices with potent ACTH prepns. (3-20 lU/mg.) or (b) adequate replacement with cortisone or hydrocortisone regimens, the dosages of which (0.83-1.2 mg./kg./day) had completely corrected the disturbed carbohydrate metabolism of adrenalectomized dogs (which were on minimal doses of DCA). Both ACTH and the steroid regimens elevated the renal functions of the dogs to 1/2 - 2/3 of the expected normal values, but never to normal. Yet concomitantly, the carbohydrate metabolism was restored to normal. In the ACTH studies, too, the adrenal gland wts. were within the normal range and evidence for hyperplasia was apparent. Even with prolonged admn. of ACTH, the effect of any single intramusc. dose produced transient increases in renal functions. The effect of the steroids was less transient. ACTH and the steroids did not restore the hypophysectomized dog''s ability to excrete water to the same degree as does growth hormone, nor did they induce a"polyuria. It was concluded that the adrenocortical atrophy is one of the factors responsible for the reduction in renal functions of hypophysectomized dogs. Conversely, adrenal steroids are important in the regulation of normal renal functions. The decrease in GFR and RPF in the hypophysectomized dog is on the basis of renal hemodynamic changes and not morphologic changes.