[The endothelial cell: a cell structurally simple but functionally very complex]

Vascular endothelium is morphologically similar to a simple squamous epithelium that lines the internal surface of vessels. These cells, even if structurally simple, are functionally very complex. They regulate vascular tone by producing vasodilators such as prostacyclin and nitric oxide and vasoconstrictors such as endothelin. In addition, endothelial cells express activators and inhibitors of coagulation, fibrinolysis and platelet aggregation. Alterations of the functional equilibrium of endothelial cells might be related to the development of many cardiovascular diseases.