The effects of a nonselective beta-adrenergic blocking drug with beta-2 agonist activity (dilevalol 200 mg) on proteinuria and renal hemodynamics were evaluated in a double-blind crossover study versus an ACE inhibitor (enalapril 5 mg) in eight patients with glomerulonephritis, moderate renal function impairment and proteinuria greater than 1 g/24 hr. Patients were studied after a one week placebo phase while off all other medications, except steroids in a few cases, and after three weeks of treatment. A 10-day placebo washout perod was included between the various drug treatments. During each period renal hemodynamics were measured by clearance techniques, and urinary protein excretion as well as fractional clearance of albumin and IgG were determined. Both drugs reduced mean arterial pressure and proteinuria to a similar extent [mean arterial pressure: placebo 108 +/- 13 mm Hg; dilevalol 103 +/- 11 mm Hg (P less than 0.05); enalapril 103 +/- 12 mm Hg (P less than 0.05); protein excretion: placebo 5.1 +/- 4.2 g/day; dilevalol 3.3 +/- 3.0 g/day (P less than 0.05); enalapril 2.8 +/- 2.8 g/day (P less than 0.05)]. The antiproteinuric effect was greater with enalapril than dilevalol. Dilevalol reduced GFR [baseline inulin clearance: 73.3 +/- 38 ml/min/1.73 m2; after dilevalol: 63.3 +/- 28 ml/min/1.73 m2 (P less than 0.05)] and the decrease of proteinuria correlated positively with the reduction of GFR. Enalapril did not significantly lower the GFR (inulin clearance during enalapril 66.8 +/- 23 ml/min/1.73 m2) and the reduction of proteinuria did not correlate with the lowering of the GFR.(ABSTRACT TRUNCATED AT 250 WORDS)