[The influence of the renin-angiotensin system on autoregulation of renal blood flow and intrarenal hemodynamics (author's transl)].

The discussion of renal hemodynamics has to include three phenomena: the autoregulation of renal blood flow, the existence of different intrarenal perfusion compartments, and the intrarenal renin-angiotensin-system. The autoregulation of renal blood flow is characterized by the constancy of renal blood flow inspite of a wide range of renal perfusion pressure (70-220 mm Hg). This is due to the ability of the kidney to adjust vascular resistance to pressure changes. Renal perfusion is not homogenous but consists of different perfusion compartments which may be distinguished according to characteristic anatomy, function and innervation. Autoregulation of renal blood flow and distribution of intrarenal perfusion to different compartments are interdependent and are shown to be both under the control of an intrarenal "local" renin-angiotensin system.