Endothelium-Dependent Hyperpolarizing Factor: A Significant Influence on Vascular Dilatation in Health and Disease

Christopher J Garland

《Journal of Medical Sciences》 24卷2期 (2004/04) Pp. 59-69

並列摘要

Endothelium-dependent hyperpolarizing factor or EDHF underlies nitric oxide and prostacylin independent arterial relaxation. As the influence of EDHF increases with decreasing artery size, it appears to play an important role in the control of blood pressure and flow. Initially suggested to represent a diffusible factor, EDHF is now recognised as a pathway encompassing a variable input in different arteries from a factor(s) and the spread of hyperpolarizing current from the endothelium to the smooth muscle. Key to unravelling this pathway has been the demonstration that hyperpolarization within the endothelium can be blocked using a combination of the toxins apamin and charybdotoxin. As a consequence, the relaxation of vascular smooth muscle, which represents the end point of the EDHF-pathway, is also blocked. This review discusses the evidence that the EDHF pathway operates in vivo and is modified in cardiovascular disease. Also discussed are the mechanisms responsible for EDHF-evoked vasodilatation, focusing on the localization of specific potassium (K) channels in the endothelium, and that a diffusible factor, which may well be K ion released by endothelial cells, acts alongside the spread of hyperpolarization through myoendothelial gap junctions to evoke EDHF-linked relaxation. While the relative importance of each of these components can vary in different arteries, together they can explain the EDHF phenomenon.

並列關鍵字

EDHF ； endothelium ； potassium channels ； vascular disease