Baroreflex modulation of muscle sympathetic nerve activity during posthandgrip muscle ischemia in humans
Baroreflex modulation of muscle sympathetic nerve activity during posthandgrip muscle ischemia in humans
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DOI：
10.1152/jappl.2001.91.4.1679
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发表时间：
2001-10-01
影响因子：
3.3
通讯作者：
Crandall, CG
中科院分区：
文献类型：
--
作者：
Cui, J;Wilson, TE;Crandall, CG
为了确定肌肉代谢受体刺激是否改变肌肉交感神经活动（MSNA）的压力反射控制，MSNA，逐搏动脉血压（Finapres）和心电图记录在11名健康受试者在仰卧位。受试者进行2分钟的等长握力运动，40%的最大随意收缩，然后2.5分钟的posthandgrip肌肉缺血。在肌肉缺血期间，分别静脉推注硝普钠和盐酸去氧肾上腺素可以降低血压，然后升高血压。与对照组（-142.7 +/-17.3 units. beat（-1）. mmHg（-1））相比，在握力后肌肉缺血（-201.9 +/-20.4 units. beat（-1）. mmHg（-1））期间，MSNA和舒张压之间关系的斜率更负（P <0.001）。心率和收缩压之间的关系的斜率没有观察到显著变化。然而，这两条曲线在运动后缺血期间移动，以适应这种情况下发生的血压和MSNA升高。这些结果提示，在握力后肌肉缺血时，刺激肌肉代谢受体可提高MSNA对压力感受性反射的调节敏感性，而对心率的调节敏感性则无明显变化。
To identify whether muscle metaboreceptor stimulation alters baroreflex control of muscle sympathetic nerve activity (MSNA), MSNA, beat-by-beat arterial blood pressure (Finapres), and electrocardiogram were recorded in 11 healthy subjects in the supine position. Subjects performed 2 min of isometric handgrip exercise at 40% of maximal voluntary contraction followed by 2.5 min of posthandgrip muscle ischemia. During muscle ischemia, blood pressure was lowered and then raised by intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure was more negative (P < 0.001) during posthandgrip muscle ischemia (-201.9 +/- 20.4 units.beat(-1).mmHg(-1)) when compared with control conditions (- 142.7 +/- 17.3 units.beat(-1).mmHg(-1)). No significant change in the slope of the relationship between heart rate and systolic blood pressure was observed. However, both curves shifted during postexercise ischemia to accommodate the elevation in blood pressure and MSNA that occurs with this condition. These data suggest that the sensitivity of baroreflex modulation of MSNA is elevated by muscle metaboreceptor stimulation, whereas the sensitivity of baroreflex of modulate heart rate is unchanged during posthandgrip muscle ischemia.