Enalapril can treat the proteinuria of membranous glomerulonephritis without detriment to systemic or renal hemodynamics.

The effect of enalapril on renal hemodynamics and glomerular permselectivity was studied in eight patients with nephrotic syndrome secondary to biopsy-proven membranous glomerulonephritis. The patients received the drug in incremental doses (median, 5 mg) until 24-hour urinary protein excretion had decreased persistently by 30%. Median treatment duration was 6 weeks. Patients were studied three times: (I) after a 4-week run-in period, (II) on the final day of treatment, and (III) after a 4-week wash-out. Median 24-hour urinary protein excretion decreased on treatment from 10.45 g/d to 5.25 g/d and increased to pretreatment levels after the drug was stopped (P less than 0.05 for both changes). Fractional clearance of dextrans greater than 4.1 nm decreased on treatment, indicating both a reduction of macromolecules passing through the shunt pathway of the glomerular basement membrane (GBM) and a possible decrease in ultrafiltration coefficient. There were no significant changes in glomerular filtration rate (GFR), effective renal plasma flow (ERPF), or mean arterial blood pressure (MAP) throughout the study. The effect of enalapril in treating proteinuria appears therefore to be due to a specific intraglomerular action.