TITLE:
Endothelin A-receptors and the coronary circulation
AUTHORS:
Evangelos Polymeropoulos, Mesele Valenti, Zenon S. Kyriakides
KEYWORDS:
Endothelin; Coronary Circulation
JOURNAL NAME:
World Journal of Cardiovascular Diseases,
Vol.3 No.5,
July
25,
2013
ABSTRACT:
We
review the role of endothelin (ET) A-receptors (R) on the coronary circulation.
ET-1 maintains the normal coronary artery tone. ET-1 plasma levels are increased
during and after coronary angioplasty and this increase is related to
myocardial ischaemia rather than to mechanical artery injury. ETAR
antagonists inhibit coronary artery vasoconstriction induced by ET release
after coronary angioplasty in humans. ET promotes neointimal formation and ETAR
antagonism has been shown to inhibit restenosis after angioplasty in the
animal model but not in humans. ETAR blockade increases coronary
blood flow, dilates distal coronary arterial segments and decreases coronary
vascular resistance. Coronary collaterals are less sensitive than other
coronary vessels to ET-1. ETAR blockade decreases collateral blood
flow and, consequently, perfusion of the ischemic myocardium.