Urine aldosterone radioimmunoassay: validation of a method without chromatography.

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, congenital adrenal hyperplasia, and primary aldosteronism determined by this method agreed closely (r = 0.95, P less than 0.01) with values obtained using a standardized chromatographic method. This simplified assay represents a significant advance in out capabilitites for evaluating patients for abnormalities in aldosterone physiology.