Endothelial Dysfunction in Hypertension

Abstract

Hypertension is an important risk factor for the development of atherosclerosis and endothelial dysfunction may be a key mechanism. The nitric oxide mediated vasodilator function of the endothelium has been widely studied as a test of endothelial integrity in patients with hypertension and impaired basal and muscarinic agonist stimulated components of nitric oxide mediated vascular tone have been found in coronary, forearm and cutaneous resistance vessels and in coronary and forearm conduit vessels. The underlying abnormalities of these changes are unknown but it is likely to be a secondary phenomenon due to increased blood pressure. However, endothelial dysfunction as assessed by response to muscarinic agonists does not occur in all patients and antihypertensive therapy so far has been mostly unable to reverse it. Although widely used the response to acetylcholine has some shortcomings and it remains to be established what parameter best reflects endothelial dysfunction. The relationship of such abnormalities to the present or future atherosclerosis needs to be defined.

Key Words:

• Endothelium
• nitric oxide
• acetylcholine
• substance P
• flow mediated dilation
• forearm
• coronary circulation