THE VASCULAR ENDOTHELIUM IN DIABETES AND HYPERTENSION

Purpose: To review recent research into the function of endothelial cells in relation to diabetes and hypertension, and the implications for cardiovascular control. Endothelial functions: Endothelial cells extract and inactivate circulating hormones, convert inactive precursors into vasoactive products, and synthesize and secrete vasodilator and vasoconstrictor mediators, which also modify platelet function and cell growth. Diabetes: Abnormalities in endothelial cell morphology and function are recognized features of diabetes. Diminished endothelium-dependent relaxation and enhanced endothelium-dependent contraction have been described. Hypertension: Similar defects in endothelial cell function have been demonstrated in animal and human hypertension. These might lead to increased vascular tone, vasospasm, platelet activation and atheroma. Therapy: Certain drugs modify or mimic endothelium-derived mediators. Endothelial dysfunction may contribute to cardiovascular pathology, but the precise clinical and therapeutic significance of modifying endothelial function remains to be determined.