Use of oral converting enzyme inhibitor, captopril for lateralizing renal venous renin activity

Captopril was administered prior to renal vein renin sampling in an attempt to select patients amenable to surgical treatment for renin dependent hypertension. Renal venous blood for plasma renin activity was taken only after captopril stimulation. Sampling from the antecubital vein before and after this provocation showed a marked rise in renin, thereby confirming the efficacy of the test. Elimination of the initial selective renal vein sampling shortens the catheterization period without affecting the accuracy and dependability of the procedure.