Role of hypovolemia in the impaired water diuresis of adrenal insufficiency.

Abstract

ABSTRACT Impaired water diuresis in adrenal insufficiency is rapidly corrected by glucocorticoid. The defect in water excretion has been attributed to hypovolemia consequent to sodium deficit. The role of hypovolemia in this defect was evaluated by observing the effect of corticoids on water diuresis in normal subjects made hypovolemic by sodium depletion. In addition the patterns of diuresis in these subjects were compared with those of patients with adrenal insufficiency maintained on mineralocorticoid but not given glucocorticoid. It was found that hypovolemia significantly impaired water diuresis in normal subjects, but that glucocorticoid had no effect on this change. The impaired water diuresis observed in patients with Addison's disease differed from that of the hypovolemic subjects. In normals made hypovolemic most of the change in water diuresis was due to increased reabsorption of fluid in the proximal nephron. In Addisonians, however, a major portion of the impairment was due to diffusion of wa...