Does brachial artery flow-mediated vasodilation provide a bioassay for NO?
Does brachial artery flow-mediated vasodilation provide a bioassay for NO?
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DOI：
10.1161/hypertensionaha.113.01578
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发表时间：
2013-08
期刊：
影响因子：
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通讯作者：
Richardson RS
中科院分区：
文献类型：
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作者：
Wray DW;Witman MA;Ives SJ;McDaniel J;Trinity JD;Conklin JD;Supiano MA;Richardson RS
本研究旨在更好地确定一氧化氮（NO）在年轻健康人肱动脉血流介导的血管舒张（FMD）中的作用。对8名志愿者（26 ± 1岁）在前臂循环阻断5分钟之前和之后，在动脉内输注内皮型一氧化氮合酶（eNOS）抑制剂L-NMMA（0.48 mg/dl/min）和不输注内皮型一氧化氮合酶（eNOS）抑制剂L-NMMA（0.48 mg/dl/min）的情况下，测定肱动脉血流速度和直径（超声多普勒）。进行对照（CON）和L-NMMA试验时，将封堵环置于传统远端位置以及测量部位近端。在远端套囊试验中，L-NMMA显著减少但未消除FMD（8.9 ± 1.3至6.0 ± 0.7%，CON vs. L-NMMA，P = 0.02），L-NMMA对近端套囊放置的FMD无影响（10.6 ± 1.2至12.4 ± 1.7%，CON vs. L-NMMA，P = 0.39）。当考虑L-NMMA后剪切刺激的减少时，远端（0.26 ± 0.02至0.23 ± 0.03，CON vs. L-NMMA，P = 0.40）或近端（0.23 ± 0.08至0.23 ± 0.03，CON vs. L-NMMA，P = 0.89）FMD试验均未观察到药物差异。这些研究结果挑战了NO是肱动脉FMD的强制性的断言，并质疑该程序在年轻健康人中无创测定NO生物利用度的灵敏度。
This study sought to better define the role of nitric oxide (NO) in brachial artery flow-mediated vasodilation (FMD) in young, healthy humans. Brachial artery blood velocity and diameter were determined (ultrasound Doppler) in eight volunteers (26 ± 1 yrs) before and after 5-min forearm circulatory occlusion with and without intra-arterial infusion of the endothelial nitric oxide synthase (eNOS) inhibitor L-NMMA (0.48 mg/dl/min). Control (CON) and L-NMMA trials were performed with the occlusion cuff placed in the traditional distal position, as well as proximal to the measurement site. FMD was significantly reduced, but not abolished, by L-NMMA in the distal cuff trial (8.9 ± 1.3 to 6.0 ± 0.7%, CON vs. L-NMMA, P = 0.02), with no effect of L-NMMA on FMD with proximal cuff placement (10.6 ± 1.2 to 12.4 ± 1.7%, CON vs. L-NMMA, P = 0.39). When the reduction in shear stimulus following L-NMMA was taken into account, no drug difference was observed for either distal (0.26 ± 0.02 to 0.23 ± 0.03, CON vs. L-NMMA, P = 0.40) or proximal (0.23 ± 0.08 to 0.23 ± 0.03, CON vs. L-NMMA, P = 0.89) FMD trials. These findings challenge the assertion that NO is obligatory for brachial artery FMD, and call into question the sensitivity of this procedure for non-invasive determination of NO bioavailability in young, healthy humans.