[Structure and functions of the endothelium].

The vascular endothelium is a dynamic interface between blood and tissues, which releases vasoconstrictors or vasodilators regulating the vascular tone. The endothelium modulates the balance between thrombosis and haemorrhage. Activated endothelium may produce tissue factor which triggers the coagulation cascade. In different tissues, the endothelial cells become specialised and may participate to the immune response and inflammation. Various metabolic or immune stimuli may alter endothelial cell functions, induce leukocyte adhesion through expression of specialised molecules and modify the release of fibrinolytic agents, cytokines, and growth factors.