The role of the vascular endothelium

The vascular endothelium is a single layer of cells lining the internal vascular walls. It is the largest endocrine gland in humans, which for many years has been perceived mainly as a barrier between the blood and vascular smooth muscle. Today, it is known that it acts as a paracrine, endocrine and autocrine organ playing an important role in maintaining proper vascular homeostasis. The vascular endothelium regulates vascular wall tension and blood flow in vessels due to the controlled release of vasodilators [NO (nitric oxide) and PGI₂ (prostacyclin)] and vasoconstrictors (endothelins and platelet-activating factor). Maintaining the delicate balance between them is of considerable significance for the cardiovascular system.

Utmost importance of the vascular endothelium

A properly functioning vascular endothelium improves tension of the vascular walls, as well as the balance between the coagulation and fibrinolytic processes, leukocyte adhesion and transport through vascular walls, not to mention that it regulates vascular inflammatory activity. Dysfunction of endothelial secretory activity or its mechanical damage impairs this homeostasis, which leads to impaired vasodilator response, proinflammatory and procoagulant activity. Endothelial impairment results in the development of cardiovascular diseases: atherosclerosis, arterial hypertension, chronic heart failure and dyslipidemia. Vascular endothelial dysfunction is also related to diabetes, as well as gastrointestinal, hepatic and renal diseases.