Urine Aldosterone Radioimmunoassay: Validation of a Method Without Chromatography

Abstract

A simplified radioimmunoassay of urinary aldosterone is reported. Acid-hydrolyzed urine was extracted with dichloromethane and the extract assayed without further purification. Urinary aldosterone values in patients with Cushing's syndrome, low and normal-renin essential hypertension, congential adrenal hyperplasia, and primary aldosteronism determined by this method agreed closely (r = 0.95, P < 0.01) with values obtained using a standardized chromatographic method. This simplified assay represents a significant advance in our capabilities for evaluating patients for abnormalities in aldosterone physiology.