Once thought to represent an inert lining in blood vessels, an increasing number of vital functions of the vascular endothelium have emerged in recent years. Among its many functions are the production of anti-platelet and anti-thrombotic agents and regulation of vascular tone through the vasodilator nitric oxide and vasoconstrictors, such as endothelin-1 and angiotensin II. Understanding the central role that endothelial function has in maintaining cardiovascular homeostasis has lead to the concept that endothelial dysfunction may also play an important role in cardiovascular disease. Reduction in nitric oxide function has been recognized in a wide range of conditions such as hypertension, hypercholesterolaemia, diabetes, menopause, and heart failure. Indeed, abnormal activity of a number of endothelial mediators may be a feature of many forms of cardiovascular disease.
The present understanding of the role of the endothelium in health and disease has resulted from both animal experiments and cl