IMPAIRMENT OF ARGININE INDUCED GROWTH HORMONE RELEASE AFTER THREE DAYS TREATMENT WITH DEPOT-ACTH

Abstract

ABSTRACT The growth hormone (GH) response to arginine infusion in 11 normal subjects and 4 patients with Addison's disease on maintenance replacement doses of cortisone and fludrocortisone was studied before and 24 h following the administration of 1 mg Synacthen-Depot® (tetracosactid) daily for 3 days. The mean peak GH levels during arginine infusion tests were significantly decreased after ACTH-treatment (3.8 vs. 32.1 ng/ml), all peak values being below the normal range. The patients with Addison's disease either showed very low GH response in the pre-treatment test followed by a small change after ACTH (3 patients) or a low normal response in the pre-treatment test with a depressed response after ACTH (1 patient). Based on the results of the present study and those previously reported by others we suggest that the acute administration of ACTH induces GH release but that repeated administration of ACTH leads to a GH depletion of the pituitary gland and decreased response to stimulation tests. This effect is not mediated through endogenous cortisol release.