Corticosteroid metabolism during the combined administration of ACTH and catecholamines.

Abstract

Abstract Various doses of epinephrine or norepinephrine were added to ACTH infusions and administered intravenously from 8 A.M. till 4 P.M. to 94 normal men and 51 normal women. Corticosteroids in plasma, red blood cells, and urine were measured. Plasma and red blood cell corticosteroid curves were analyzed by means of an analog computer. The results were compared with those obtained with standard ACTH infusions in 42 normal men and 42 normal women. In men 2 effects were observed: a significant decrease of plasma corticosteroid concentration during and at the end of the infusion when small amounts of catecholamines were added to the ACTS solutions and a significant increase of the plasma corticosteroid concentration with doses at least 5 times larger of catecholamines. Using the analog computer analysis it could be shown that these effects were due to a constant increase in removal rate r when more than 25 ng. per minute per kilogram of catecholamines was added to the ACTH infusion and an increase in production rate p probably due to a contraction of the readily miscible pool when large doses (120 ng. per minute per kilogram) were administered. In women no effect on removal rate, but only the increase in the p factor was found. The increase in free corticosteroid removal rate observed in men is not due to an accelerated A ring hydrogenation and conjugation of the corticosteroids or to an additional storage of corticosteroids in the red blood cells. Neither is an increased conversion of cortisol to cortisone the cause of the observed phenomenon. The sex difference noted during the combined administration of ACTH and catecholamines might explain certain of the sex differences in stress-induced pathology.