[Angiotensin II type-1-receptor antagonists from the viewpoint of nephrology]

ACE (Angiotensin Converting Enzyme) inhibitors and angiotensin II type 1 receptor antagonists increase the effective renal plasma flow dose dependently, whereas glomerular filtration rate does not change. Both substances reduce dose dependently arterial blood pressure, glomerular capillary pressure and proteinuria and are probably comparably renoprotective due to haemodynamic and non-haemodynamic (e.g. antiproliferative) effects. These data indicate that the renoprotective effects of ACE inhibitors and angiotensin II receptor antagonists are the results of inhibition of angiotensin II and not due to inhibition of bradykinin degradation. Several studies suggest an additive renoprotective effect of ACE inhibitors and angiotensin II receptor antagonists. However, controlled clinical studies are lacking. Experimental data suggest that the combination of AT1 and AT2 receptor blockers or treatment with ACE inhibitors reduce more effectively inflammatory cell infiltration into the kidney than angiotensin II type 1 receptor antagonists alone. Long-term clinical trials using angiotensin II type 1 receptor antagonists are needed before these substances can be recommended as comparably renoprotective as ACE inhibitors.