Pseudohypoaldosteronism: Persistence of Hyperaldosteronism and Evidence for Renal Tubular and Intestinal Responsiveness to Endogenous Aldosterone

Abstract

A 9-yr-old patient, diagnosed during infancy as pseudohypoaldosteronism, was investigated after a prolonged period of spontaneous recovery. Hyperaldosteronism and hyper-reninemia were observed on normal sodium intake (urinary tetrahydroaldosterone was 168–243 μg/24 hr, aldosterone secretion rate was 1200 μg/24 hr and plasma renin activity was 3.3 ng/ml/hr). Administration of spironolactone increased urinary and fecal sodium excretion. On low sodium intake a further rise in aldosterone secretion was obtained in the presence of decreased urinary sodium excretion. Fecal sodium values paralleled urinary sodium changes and were consistent with a responsiveness of the colon to endogenous aldosterone. The binding of 3H-aldosterone by a nuclear fraction from the mucosa cells of the sigmoid colon was within the normal range. Renal function was normal except for decreased maximum glucose tubular reabsorption. The data suggest that the renal tubule and the intestine were responsive to changes of aldosterone secretion, and that the state of chronic hyperaldosteronism might be related to another abnormality in sodium tubular handling.