Endothelial cell function: biologic and physiologic functions in health and disease.

Endothelial cells (EC) form a monolayer with a strategic role in the control of many physiologic and biologic pathways. Although the endothelium initially was thought to be an inert and passive barrier of the vasculature, the diverse functions of EC have been better defined in the past decade. EC play an important role in the control of coagulation, vasomotor tone, growth of vascular smooth muscle cells, white cell trafficking, ischemic and reperfusion injuries, and the development of arteriosclerosis. Owing to their location in the arterial tree, EC also are considered a potential target for gene therapy. The introduction of foreign DNA into EC by in vitro transfection with viral vectors has produced encouraging results when using genes that encode for proteins such as insulin and urokinase. The seeding of EC onto vascular grafts appears to convey the thromboresistant properties of saphenous vein to an artificial surface. This review focuses on the important biologic and physiologic functions of EC in health and disease.