[Vasoactive peptides of endothelial origin. Therapeutic perspectives].

The role of the endothelium in vascular tone is well established. New physiopathological concepts were brought about by the discovery of endothelium derived vasoactive substances such as the vasodilators prostacyclin and endothelium-derived relaxing factor (EDRF) or the vasocontrictors endothelin and other putative endothelium-derived contracting factors (EDCF). Their discovery led to new therapeutic concepts in vascular, respiratory and infectious diseases. Prostacyclin is a prostaglandin derived from arachidonic acid which has an inhibitor effect on platelet aggregation. It also has a vasodilator effect on vascular smooth muscles cells. Prostacyclin analogues are choice vasculoactive pharmacological agents for patients with thromboangiitis obliterans or severe peripheral vascular disease, whether arteriosclerotic or not. The effect of EDRF is vascular dilatation, predominately in the arteries but also in the veins, including vessels in grafted tissues. EDRF also inhibits platelet aggregation and adhesion. Inversely, the endothelium can also release EDCF which has a vasoconstrictor effect. Endothelin, a recently identified 2429 kD EDCF is active in both arteries and veins and is implicated in physiologic regulation of vasomotricity.