Contrasting acute effects of captopril and nifedipine on renal function in renovascular hypertension.

In order to assess the determinants of renal function deterioration induced by angiotensin-converting enzyme inhibition (ACEI) in renovascular hypertension, studies were performed in patients with bilateral stenosis (BS; n = 12) and stenosis of a solitary kidney (SK; n = 10). Acute administration of captopril was associated with a consistent fall in glomerular filtration rate in 5 of 12 patients with BS and 8 of 10 with SK. Overall, glomerular filtration rate decreased by 22 +/- 7%, while mean arterial pressure decreased by only 8 +/- 2% and renal plasma flow remained unaltered. The ACEI-induced change in glomerular filtration rate was unrelated to blood pressure or basal plasma renin activity, but it was inversely related to pre-ACEI filtration fraction. In a comparative study conducted in 6 BS and 4 SK patients, acute administration of nifedipine was associated with a change in glomerular filtration rate of 13 +/- 5% and no change in renal plasma flow, despite a marked decrease in mean arterial pressure of 19 +/- 4%. In contrast, in the same patients, glomerular filtration rate fell by 23 +/- 12%, renal plasma flow did not change and mean arterial pressure fell slightly by 7 +/- 3% after ACEI.(ABSTRACT TRUNCATED AT 250 WORDS)