Different effects between antihypertensive drugs on nephrotic-range proteinuria in renovascular hypertension

A 61-year-old man developed renovascular hypertension characterized by nephrotic-range proteinuria. When he was treated with a calcium channel blocker, glomerular filtration fraction was 0.26 and massive proteinuria ranging from 10 to 15 g/day persisted. An angiotensin-converting enzyme inhibitor markedly reduced the proteinuria to 1-2 g/day with a filtration fraction of 0.20. After the antihypertensive drug was switched to a beta-blocker, the filtration fraction was 0.23 and urinary protein excretion was 3-4 g/day. Blood pressure control was comparable by each drug. These findings suggest a role of intraglomerular hydraulic mechanism in the etiology of massive proteinuria in renovascular hypertension.