Endothelial Dysfunction in Hypertension

摘要

The endothelium has an important role in control of vascular functions. Endothelial factors, particularly nitric oxide, are involved in the control of vascular smooth muscle and in numerous other regulatory functions, which contribute to the protective role of the endothelium. Endothelium-derived NO may contribute to the overall regulation of arterial blood pressure by its ability to relax vascular smooth muscle. Experimental and clinical data indicate that endothelial function is damaged in hypertension. Endothelial dysfunction in hypertension may be a consequence of different mechanisms involved in regulation of blood pressure. The impairment of endothelial function is associated with either decreased NO bioavailability (impaired release or decreased NO efficiency) and/or concomitant release of endothelial contracting factor which impair the affect of NO. It is presently unclear whether endothelial dysfunction is a primary abnormality or a consequence of the elevated blood pressure values. There are the data in favour of direct damage of the endothelial cells secondary to a prolonged increase of the haemodynamic load and shear stress. However, in normotensive offsprings of hypertensive parents, an early alteration of endothelium-dependent vasodilatation in the forearm was observed.