Influence of age, renal disease, hypertension, diuretics, and calcium on the antidiuretic responses to suboptimal infusions of vasopressin

Abstract The antidiuretic response in water loaded individuals to a constant infusion of vasopressin, less than the amount necessary to concentrate the urine to the maximum (8 mU. per hour), has been followed in normal subjects, both young and old, in patients with renal disease (acute and chronic glomerulonephritis and chronic pyelonephritis), in patients with severe hypertension, and in normal subjects following the administration of diuretics (mercurial, chlorothiazide, acetazolamide, aminophylline, mannitol, and calcium gluconate). Marked interindividual variations were observed in the antidiuretic responses to infused vasopressin even in normal subjects. On the other hand, intraindividual studies showed little variation. The ability of the cellular membranes in the distal nephron to become more water permeable in response to this specified quantity of antidiuretic hormone (ADH) was possibly diminished in only those subjects with chronic pyelonephritis and the most severe hypertension. The diminished response to vasopressin in these patients was more likely due to a defect in the countercurrent concentrating mechanism in the inner medulla than to a relative inability of vasopressin to increase membrane permeability to water in the distal nephron. None of the diuretics, including calcium gluconate, affected appreciably the ability of vasopressin to increase water permeability in the distal nephron.