A DOUBLE-BLIND PLACEBO-CONTROLLED COMPARI SON OF THE EFFECTS OF BETA-RECEPTOR BLOCKERS AND ACE-INHIBITOR ON RENAL HEMODYNAMICS AND PROTEINURIA IN CHRONIC GLOMERULONEPHRITIS

Background and objective: In patients with chronic glomerular nephropa thy associated arterial hypertension and proteinuria are considered to be cardinal risk factors in the progressive deterioration of renal fu nction. Treatment regimens which reduce proteinuria and hypertension i mprove prognosis. The effect of the new beta-receptor blockers compare d to common ACE-inhibitors is of special interest. Patients and method s: The studied cohort consisted of 11 patients with CGN, hypertension and proteinuria >400 mg/24 h. Four drugs were given for 4 weeks, doubl y blinded a nd randomized according to a ''Latin-square design'': Celi prolol (beta-1-antagonist, beta-2-agonist, 200 mg/d), Atenolol (select ive beta-1-antagonist, 50 mg/d), Ramipril (ACE-inhibitor, 2,5 mg/d) an d placebo. There was a two-week wash-out phase between each of the fou r treatment phases. At the end of each treatment phase glomerular filt ration rate (GFR) and effective renal plasma flow (ERPF) were measured by inulin and para-aminohippuric acid (PAH) clearance. Proteinuria wa s determined in the course of a three-day collection period at the end of each treatment phase. During this period blood pressures were meas ured with a continuous 24-hour blood pressure monitor. Results: Mean a rterial blood pressure (MAP) was significantly reduced, compared with placebo, by all three antihypertensives (108 +/- 9 mm Hg with placebo, 98 +/- 12 mg Hg with atenolol, 101 +/- 11 mm Hg with celiprolol and 9 8 +/- 8 mm Hg with ramipril; P < 0.01). Celiprolol produced a signific ant rise in ERPF (322 +/- 109 ml/min with placebo, 391 +/- 110 ml/min with celiprolol; P < 0.05). GFR was slightly, but not significantly, r educed by celiprolol and atenolol. Filtration fraction remained unchan ged with atenolol and celiprolol, while it was slightly, but not signi ficantly reduced with ramipril. Compared with the placebo, all three d rugs significantly reduced proteinuria (P < 0.05): 1.8 +/- 1.3 g/24 h with placebo, 1.2 +/- 1.2 g/24 h with atenolol, 1.2 +/- 1.1 g/24 h wit h celiprolol and 1.4 +/- 1.4 g/24 h with ramipril. Conclusion: These d ata indicate that, in addition to ACE inhibitors, the new generation o f beta-receptor blockers in particular, because of their vasodilator a ction, favourably influence proteinuria and renal blood flow in patien ts with CGN and arterial hypertension.