The action of cortisone and desoxycorticosterone acetate on glomerular filtration rate and sodium and water exchange in the adrenalectomized dog.

Adrenal failure causes a complex disturbance of renal function and of sodium and water exchange. In the dog, as in man, the ability to conserve sodium is impaired (1, 2), there is a fall in glomerular filtration rate and renal blood flow (3-6), and diuresis from water ingestion is much delayed (7, 8). There have been many reports of the effects of corticosteroids on discrete renal functions such as filtration rate or excretion of water and electro-lytes in adrenal insufficiency. There have, however , been few attempts to correlate the changes in these renal functions, one with another and with the level of bodily hydration. Thus, from existing data, the effects of changes in filtration rate on other renal functions, or of changes in bodily hy-dration on filtration rate, cannot be clearly defined in relation to the action of corticosteroids. The steroids most examined for their renal effects have been desoxycorticosterone acetate (DCA) and, to a much lesser extent, cortisone. Though DCA appears to act mainly on electrolyte excretion, yet, when given in larger amounts than are needed for optimal sodium balance, it may then correct the low filtration rate of adrenalec-tomized dogs (4, 8, 9). It is not clear, however, whether this last effect is mainly or wholly dependent on excessive sodium retention, for no comparable studies appear to have been made at deliberately optimal levels of sodium balance (10, 11). Cortisone seems to be more active than DCA in restoring filtration rate (12-14) and water diuresis (15, 16), and, by mechanisms which are not yet understood, it can either increase or diminish the sodium output (14, 15, 17-19). There is little information about its effects in the adrenal-ectomized dog (14, 20). The investigations reported in this paper are an attempt to define more precisely the renal actions of cortisone and DCA, with special reference to their effects on filtration rate and on sodium and water exchange. EXPERIMENTAL PLAN AND METHODS Renal function was studied in two trained female mongrel dogs, before and after bilateral adrenalectomy, with the following objects: (a) to measure the effects of adrenalectomy on GFR and renal excretion of water and electrolytes, under controlled conditions of bodily hy-dration, but during escape from direct corticosteroid effects; (b) to compare the acute effects of cortisone and DCA on these renal functions, after adrenalectomy; and (c) to correlate the changes in these different renal functions with one another …