Influence of time factor on the restoration of adrenal weight and cortical functions in hypophysectomized rats.

Abstract

It has been shown that repeated doses of a long-acting synthetic ACTH preparation (Synacthen Depot®) are able to restore adrenal function in rats with adrenal atrophy (induced by hypophysectomizing the animals and leaving them untreated for varying periods of time). Restoration of responsiveness to single doses of synthetic ACTH (Synacthen®) can be effected after a relatively short time (10 days’ treatment is sufficient for this purpose); restoration of adrenal weight, how ever, calls for at least 30 days’ treatment with the doses used in this study. In other words, the animals’ adrenals, though greatly reduced in size, are nevertheless capable of displaying a virtually normal response to stimulation. This discrepancy indicates that, during the stimulation test, they must be more active than normal adrenals. This phenomenon cannot be accounted for at present.