Effect of Angiotensin Blockade and Converting Enzyme Inhibition on Renovascular Hypertension: Comparison Between Unilateral and Bilateral Renal Artery Stenosis

Abstract

The response to angiotensin II analog infusion during sodium deletion and the effects of a one-month captopril treatment were compared between 15 re novascular hypertensive patients with unilateral and 6 with bilateral renal ar tery stenosis. Plasma renin activity, its response to sodium depletion, and the renal vein renin ratio during sodium depletion were greater in unilateral than in bilateral stenosis. A fall in diastolic blood pressure induced by analog infusion during sodium depletion was correlated with the preinfusion plasma renin ac tivity and with the renal vein renin ratio. Treatment with captopril showed a comparable hypotensive effect in unilateral and bilateral stenosis. The reduc tion in blood pressure was not correlated with the pretreatment renin levels or changes in blood pressure observed during analog infusion. Plasma renin activ ity rose and plasma aldosterone level fell in all patients. These results indicate that the mechanism maintaining high blood pressure is more renin dependent in unilateral than in bilateral stenosis and that the long-term effect of captopril does not not depend solely on the suppression of the renin-angiotensin-aldoster one system.