A COMPARATIVE STUDY OF ALDOSTERONE AND OTHER ADRENAL STEROIDS IN ADRENALECTOMIZED DOGS1

Abstract

The minimum maintenance dose of aldosterone and the free alcohols of DOC, cortisone and hydrocortisone, when given subcutaneously to adrenalectomized dogs in 10% alcohol in divided doses twice daily is as follows: Aldosterone, approximately 10 [mu]g/dog/day; DOC 250-125 [mu]g/dog/day; cortisone and hydrocortisone, 5000 [mu]g/dog/day. Thus, the daily requirement for aldosterone, under the conditions of these experiments, is 12-25 times less than that required for DOC and is but l/500th of the daily dose necessary for maintenance when either of the C11-oxysteroids are used. If the dogs are assayed using DCA in oil, the minimum dose preserving normality in tests similar to those presented here and performed under identical conditions, is 300-500 [mu]g/ dog/day. This is 30-50 times more steroid than the 10 fig daily requirement for maintaining adrenalectomized dogs with aldosterone. Aldosterone in low dosage is less effective in regulating serum K levels than it is in maintaining a normal serum Na. In this respect it appears to differ from DOC, for aldosterone dogs receiving sub-maintenance doses and exhibiting severe symptoms of hyperpotassemia may present no detectable deviations from normal in serum Na. A larger dose of aldosterone is requisite to prevent a slow decline in arterial pressure than is necessary to keep the serum electrolyte pattern normal. Aldosterone, although possessing certain physiological properties characteristic of DOC, also exhibits activity different from desoxycorticosterone and peculiar to itself.