Effects of lower body negative pressure on sympathetic discharge to leg muscles in humans.
Effects of lower body negative pressure on sympathetic discharge to leg muscles in humans.
复制标题
下半身负压对人类腿部肌肉交感神经放电的影响。
DOI：
10.1152/jappl.1987.63.6.2558
复制
发表时间：
1987
期刊：
影响因子：
--
通讯作者：
LeimbachJr,WN
中科院分区：
文献类型：
--
作者：
Victor,RG;LeimbachJr,WN
最近的研究表明，非低血压直立性应激在人类引起反射血管收缩在前臂，而不是在小腿。我们使用微电极记录有意识的人腓神经的肌肉交感神经活动（MSNA），以确定在非低血压下体负压（LBNP）期间心脏压力感受器的卸载是否会增加腿部肌肉的交感放电。LBNP从-5到-15 mmHg对动脉压或心率没有影响，但导致中心静脉压逐渐下降，腓总肌细na相应大幅上升。在LBNP仅为-5 mmHg时，总MSNA（突发频率X平均突发幅度）增加了61 +/- 22%（与对照组相比，P < 0.05），在LBNP为-15 mmHg时，总MSNA（突发频率X平均突发幅度）逐渐上升到比对照组高149 +/- 29% （P < 0.05）。主要的新结论是，非降压性LBNP对腿部和手臂的肌肉交感神经流出有强有力的刺激作用。在人类直立应激时，心脏压力反射似乎会触发所有四肢骨骼肌的大量交感放电。
Recent studies indicate that nonhypotensive orthostatic stress in humans causes reflex vasoconstriction in the forearm but not in the calf. We used microelectrode recordings of muscle sympathetic nerve activity (MSNA) from the peroneal nerve in conscious humans to determine if unloading of cardiac baroreceptors during nonhypotensive lower body negative pressure (LBNP) increases sympathetic discharge to the leg muscles. LBNP from -5 to -15 mmHg had no effect on arterial pressure or heart rate but caused graded decreases in central venous pressure and corresponding large increases in peroneal MSNA. Total MSNA (burst frequency X mean burst amplitude) increased by 61 +/- 22% (P less than 0.05 vs. control) during LBNP at only -5 mmHg and rose progressively to a value that was 149 +/- 29% greater than control during LBNP at -15 mmHg (P less than 0.05). The major new conclusion is that nonhypotensive LBNP is a potent stimulus to muscle sympathetic outflow in the leg as well as the arm. During orthostatic stress in humans, the cardiac baroreflex appears to trigger a mass sympathetic discharge to the skeletal muscles in all of the extremities.