A screening test for renovascular hypertension by means of orally active angiotensin I converting enzyme inhibitor, captopril (SQ 14225).

Orally active converting enzyme inhibitor (Captopril, SQ 14225) was administered in a dose of 50 mg to 12 normotensive subjects (Group I), 26 essential hypertensive patients (Group II) and 8 renovascular hypertensive patients (Group III). In Group III, 5 of 8 patients had control plasma renin activity (PRA) similar to those in Group I and II patients, but the PRA response to the administration of Captopril was greater in 7 of 8 patients than that in Groups I and II. These 7 patients had either bilateral or unilateral main renal artery stenosis. Captopril caused no increase in PRA in the remaining 1 who had unilateral renal artery stenosis with contralateral renal aplasia. It is concluded that this provocation test is useful as a screening procedure for the diagnosis of renovascular hypertension.