| Title | Endothelin-1 is a key mediator of coronary vasoconstriction in patients with transplant coronary arteriosclerosis. | | Author(s) | Larose E, Behrendt D, Kinlay S, Selwyn AP, Ganz P, Fang JC | | Institution | Multidisciplinary Department of Cardiology, Quebec Heart and Lung Institute at Laval Hospital and Laval University, Quebec, Canada. | | Source | Circ Heart Fail 2009 Sep; 2(5):409-16. | | Abstract | BACKGROUND: Transplant coronary arteriosclerosis (TCA) is the principal long-term complication in cardiac transplant recipients. The mediators responsible for vascular proliferation and vasoconstriction typical of TCA remain largely unknown. We tested whether endothelin-1 (ET-1), a potent vasoconstrictor and mitogen, contributes to the pathogenesis and manifestations of TCA.
METHODS AND RESULTS: BQ-123, an ET-1 receptor-A antagonist, was infused into a coronary artery (40 nmol/min for 60 minutes) of 18 subjects, 6 + or - 4 years after transplantation. Vasomotor responses were measured in the infused artery and in a noninfused control artery in patients with (n=10) and without (n=8) advanced TCA (108 total coronary segments). Changes in diameters were compared at 15-minute intervals up to 60 minutes. Contribution of ET-1 to coronary constrictor tone was assessed by comparing vasodilation from BQ-123 with that of the maximal vasodilator nitroglycerin (200-microg intracoronary bolus). BQ-123 dilated coronary arteries of transplanted patients (8.4% at 60 minutes versus -0.4% in noninfused arteries, P<0.001). Dilation was greater for arteries with advanced TCA defined as diameter stenosis > or = 15% (dilation 15.2% with versus 0.6% without advanced TCA, P=0.004). Judged against the response to nitroglycerin, ET-1 accounted for 53.2% of coronary tone in advanced TCA but only 12.9% without advanced TCA.
CONCLUSIONS: This study shows for the first time in humans that ET-1 is an important mediator of coronary vasoconstriction in TCA and accounts for >50% of the increased vasomotor tone. Therapeutic targeting of ET-1 may retard the development of TCA. | | Language | eng | | Pub Type(s) | Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
| | PubMed ID | 19808370 |
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