Renin-angiotensin system in an infant with malignant renovascular hypertension.

A one-year-old girl with malignant renovascular hypertension had increased levels of plasma renin activity and angiotensin II concentration in peripheral blood and in blood from the affected kidneys as compared with that from the contralateral kidney. Unilateral nephrectomy was followed by resolution of the hypertension and normalization of the activity of the renin-angiotensin system.