ETA receptors mediate vasoconstriction of large conduit arteries during reduced flow in humans
ETA receptors mediate vasoconstriction of large conduit arteries during reduced flow in humans
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DOI：
10.1097/00005344-200309000-00001
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发表时间：
2003-09-01
影响因子：
3
通讯作者：
Noll, G
中科院分区：
文献类型：
--
作者：
Spieker, LE;Lüscher, TF;Noll, G
血管紧张性由内皮源性血管舒张和收缩物质调节，主要是一氧化氮和内皮素（ET）-1。这两个调解人，这对对方的行动。响应于血流产生的剪切应力而释放。本研究的目的是描绘的贡献，内源性ET-1对血管张力的大管道动脉在减少和充血流量。用高分辨率超声回声跟踪仪连续测量8例健康人桡动脉内径。在建立稳定的基线条件后，将手腕袖带充气至超收缩压5分钟。在另外5名受试者中，在动脉内输注生理盐水或ETA受体拮抗剂（BQ-123，1 nmol/min）期间获得测量值，剂量不影响基底桡动脉直径。腕部闭塞引起桡动脉进行性血管收缩（P = 0.0001）。ETA受体拮抗剂显著减弱了腕部闭塞期间桡动脉的血管收缩（-2.7%+/-0.6% vs-6.8% 0.6%，生理盐水期间，P = 0.007）。血流介导的血管舒张不受BQ-123的影响（7.5%+/-0.8% vs 7.8%+/-1.1%，P = NS）。这项研究表明，在血流量减少的条件下，通过ETA受体激活大导管动脉的主动血管收缩。这可能在全身或局部血流减少的疾病状态中起重要作用，并表明ETA受体拮抗剂的治疗潜力。
Vascular tone is regulated by endothelium-derived vasodilating and constricting substances, mainly nitric oxide and endothelin (ET)-1. These 2 mediators, which antagonize the actions of each other. are released in response to shear-stress produced by blood flow. The aim of this study was to delineate the contribution of endogenous ET-1 on vascular tone of a large conduit artery during reduced and hyperemic flow. Radial artery diameter was continuously measured with a high-resolution ultrasonic echo-tracking device in 8 healthy subjects. After establishing stable baseline conditions, a wrist cuff was inflated to suprasystolic pressure for 5 minutes. In another 5 subjects, measurements were obtained during intraarterial infusion of saline or an ETA receptor antagonist (BQ-123, 1 nmol/min) in a dosage not affecting basal radial diameter. Wrist occlusion caused a progressive vasoconstriction of the radial artery (P = 0.0001). Vasoconstriction of the radial artery during wrist occlusion was significantly attenuated by ETA receptor antagonism (-2.7% +/- 0.6% versus -6.8% 0.6% during saline, P=0.007). Flow-mediated vasodilation was not influenced by BQ-123 (7.5% +/- 0.8% versus 7.8% +/- 1.1%, P = NS). This study demonstrates active vasoconstriction of large conduit arteries during conditions of reduced blood flow via ETA receptoractivation. This may play an important role in disease states with reduced systemic or local blood flow and indicates the therapeutic potential of ETA receptor antagonism.