Hypertension and unilateral parenchymal renal disease. Evidence for abnormal vasoconstriction-volume interaction

Hypertension was not renin-dependent in the majority of 62 hypertensive patients with seemingly unilateral renal parenchymal disease, as indicated by plasma renin activity: low in 14 (23%), normal in 40 (56%), and high in only 8 (13%). By a weighted scoring system for analysis of differential renal-vein and peripheral renin levels, 70% (16 of 23) of these patients did not give scores predictive of cure by nephrectomy. Thus, occult bilateral disease reflected by attendant volume expansion and consequent reactive renin suppression may explain the well-known disappointing cure rate after uninephrectomy in this group. Since unilateral hypersecretion of renin with a completely normal contralateral kidney is rare in this group, abnormal renal-vein and peripheral renin values should be a prerequisite for advising nephrectomy, especially when the suspected kidney shows considerable excretory function.