Metabolic effects of ACTH in the sheep.

SCOGGINS, BRUCE A., JOHN P. COGHLAN, DEREK A. DENTON, JAMES S. K. FAN, JOHN G. MCDOUGALL, CATHERINE J. ODDIE, AND ARTHUR A. SHULKES. Metabolic effects of ACTH in the sheep. Am. J. Physiol. 226( 1) : 198-205. 1974.-The effect of ACTH administration (80 IU/day) for 5 and 10 days has been studied in the sheep. Blood cortisol, corticosterone, deoxycortisol, and deoxycorticosterone levels were significantly increased with ACTH. Aldosterone levels remained unchanged and within the normal Na replete range. ACTH resulted in a significant increase in systolic and diastolic blood pressure within 24 h. This increase was sustained for the duration of ACTH treatment. Changes in blood pressure were not related to changes in external Na status or in body weight. Hypokalemic alkalosis was rapidly produced without change in urinary K excretion. Increases in both urine output and water intake were observed in all animals. Withdrawal of the ACTH stimulus resulted in rapid return of blood pressure and plasma [K] to normotensive levels associated with a natriuresis. Water turnover was normal within 7 days. The effects of ACTH in the sheep at doses to give maximal stimulation of adrenal steroid secretion, particularly the effect on blood pressure, are in contrast to those observed in other species. The rapidly induced changes in blood pressure with ACTH in the sheep suggest this may be a useful new model of experimental hypertension. provide information about the interrelationships between adrenocortical function, electrolyte metabolism, and blood pressure regulation.