The effects of cortisone and hydrocortisone on water diuresis and renal function in man.

The deficient diuretic response to water which is characteristic of patients with adrenal insufficiency can be rapidly corrected by the administration of cortisone (1-3). The mechanism of the defective diuresis and the precise nature of the response to hormonal replacement have not been established. A number of observations, chiefly in experimental animals, have suggested that administration of various adrenocortical preparations in large "pharmacologic" doses also influences water diuresis in the normal organism (4). However, no systematic study of the latter effect has been made in man. The present report describes the effects of large doses of cortisone and hydrocortisone on water diuresis, renal solute excretion, glomerular filtration rate, and effective renal plasma flow in man. Striking augmentation of the maximal rates of urine flow observed during maintained water loading was a regular occurrence. The steroids studied appear to have a specific influence upon water reabsorption by the renal tubules, an action which can be separated from their effect on renal hemodynamics.