[Regulation of kidney hemodynamics. Role of endothelial factors]

The vascular endothelium produces relaxing (PGI2 and EDRF) and contracting (endothelin) factors of the vascular smooth muscle cells. Among these, EDRF, recently identified as NO, is most important. Indeed, NO is continuously formed in the endothelial cells and can thus maintain a state of active and permanent vasodilatation. Consequently, NO may also set the systemic arterial pressure. Our experimental observations suggest that NO sets approximately 50% of the vasomotor tone of the arterial circulation including the renal circulation. In this regard, the activity of NO is not indispensable to renal blood flow autoregulation. Alterations of NO's and/or other endothelial factors' synthesis occur in a variety of cardio-vascular and renal diseases. A better understanding of the physiology and pathophysiology of the vascular endothelium will certainly allow to consider new and exciting therapeutic perspectives in these areas.