Nitric oxide and hypertension: not just an endothelium derived relaxing factor!

Abstract

The importance of endothelial nitric oxide (NO) generation in sustaining a tonic systemic vasodilatation is well established. Inhibiting NO production produces hypertension in animals and in humans and not surprisingly there has been considerable interest in establishing whether deficiencies of endothelial NO pathway activity are implicated in the aetiology of essential hypertension. The results of these investigations have been inconsistent with some suggestion that observed deficiencies of both basal and stimulated endothelial NO generation in hypertensive subjects may be an effect rather than the cause of raised arterial pressure. It is increasingly recognised that neuronal production of NO also influences cardiovascular homeostasis through its action as a neuromodulator within the autonomic nervous system. Overall NO has been shown to have sym-

Insights into human hypertension: the role of endothelial dysfunction

“…2,11 Indeed, several studies have demonstrated that low NO, whose circulating levels are considered as a surrogate of endothelial dysfunction, is an early marker in patients with common cardiovascular risk factors, such as diabetes, smoking and hypertension. 2 In a recent issue of the Journal of Human Hypertension, Srivastava et al 12 confirm that in patients with essential hypertension, NO is significantly lower than in healthy controls and that smoking habit markedly decreases NO production. The authors also examined the role of vascular cell adhesion molecule (VCAM)-1 and E-selectin, as well as the relationship between those and systolic blood pressure (SBP) and/or diastolic blood pressure (DBP).…”

“…2 Of note, endothelial dysfunction in hypertension may occur very early, even in white coat hypertension. 13 Another aspect of this complexity emerges from the therapeutic targeting of endothelium impairment.…”

“…2 Many studies over the past 10 years indicate that endothelial cells have important transport functions, act as the provision of an antithrombogenic interface, control of platelet adherence and thrombosis, as well as active actions in inflammation and vascular tone. Indeed, use of simple drugs such as aspirin may influence endothelial function in hypertension.…”

“…5 Of particular interest, in the pathophysiology of the endothelium, is the endothelial regulation of vascular tone. 2 Endothelial cells produce several vasoactive substances, and among them is NO, the most powerful vasodilator. 2 …”

“…2 Endothelial cells produce several vasoactive substances, and among them is NO, the most powerful vasodilator. 2 …”