Effects of Endothelin-1 and Endothelin-1 Receptor Blockade on Cardiac Output, Aortic Pressure, and Pulse Wave Velocity in Humans

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Abstract
Endothelin-1 (ET-1) is a potent vasoconstrictor. Its effect on arterial wave reflections and central pressure augmentation is unknown. We studied whether ET-1, in plasma concentrations present in disease, increases pulse wave velocity (PWV) and augmentation index (AIx) and therefore compromises cardiac output, and whether the ET-1 receptor blocker VML-588 (previously AXV-034343 and Ro 61–1790) prevents such effects. Nine healthy men received a 2-hour infusion with ET-1 (2.5 ng · kg −1 · min −1 ) superimposed on vehicle or VML-588 (0.05, 0.20, or 0.40 mg · kg −1 · h −1 ) (randomized order). Arterial tonometry and pulse wave contour analysis were used to assess aortic PWV and central aortic pressures and impedance cardiography for cardiac output. ET-1 slightly increased mean arterial pressure and peripheral resistance but had no significant effect on systolic blood pressure and pulse pressure. PWV increased from 5.4±0.2 to 5.7±0.3 m/s ( P P P P P <0.05). VML-588 caused a slight decrease in brachial mean arterial pressure, PWV, and AIx, and prevented the effects of ET-1 on central hemodynamics without a clear dose-response effect. In summary, ET-1 in plasma concentrations as found in renal failure and heart failure accelerates PWV, causes a disproportionate increase in central aortic systolic blood pressure and pulse pressure, and decreases cardiac output. These effects can be prevented with an ET-1 receptor blocker such as VML-588. This makes it worthwhile to focus on endothelin as a target to prevent ventricular hypertrophy and to maintain cardiac function in diseases associated with high ET-1.