Regional renal blood flow in normal and disease states.

Renal function is intimately dependent on renal blood flow. Alterations in either total or regional renal blood flow have major consequences for renal function. Through homeostatic mechanisms the kidneys are able to maintain relatively stable rates of flow over a wide range of perfusion pressures. A combination of neural, endocrine, exocrine and autocrine signals serve to regulate renal blood flow at both local and systemic levels. Alterations in the balance of these systems occur in the presence of certain pathophysiological conditions and an understanding of the subsequent changes in regional renal blood flow distribution aids in the understanding of the associated changes in renal function. The regulation and distribution of regional blood flow and the effects of surgical and pathophysiological conditions on these factors are reviewed.