Michikami D, Kamiya A, Qi F, Niimi Y, Iwase S, Mano T
Department of Autonomic Neuroscience, Division of Higher Nervous Control, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.
Environ Med. 2000 Dec;44(1):46-8.
The purpose of the present study was to evaluate the effect of hypoperfusion to the static-exercised-muscle induced by arm elevation on muscle sympathetic nerve activity (MSNA) recorded from the right tibial nerve (n= 10) by microneurography. Subjects performed static handgrip exercises (SHG) at 30% of maximal voluntary contraction (MVC) for 2 min, followed by 2 min of posthandgrip muscle ischemia (PHGMI) at the heart level (control) and with the arm elevated (50 cm above heart level). Basal heart rate, mean blood pressure and MSNA responses expressed as burst rate (bursts/min) and total MSNA (%) were unaffected by the arm-position. Heart rate response during SHG was not influenced by the arm elevation, while mean blood pressure and MSNA responses were increased by it (P<0.05). MSNA responses were increased during the second minute of the SHG period (P<0.05) and the PHGMI period (P<0.05) in the elevated arm position. In conclusion, arm elevation increased MSNA responses to SHG and PHGMI, suggesting an increased magnitude of muscle metaboreflex.
本研究的目的是通过微神经ography评估手臂抬高引起的对静态运动肌肉的低灌注对从右胫神经记录的肌肉交感神经活动（MSNA）的影响（n = 10）。受试者以最大自主收缩（MVC）的30%进行静态握力运动（SHG）2分钟，然后在心脏水平（对照）和手臂抬高（高于心脏水平50厘米）的情况下进行2分钟的握力后肌肉缺血（PHGMI）。基础心率、平均血压和以爆发率（爆发次数/分钟）和总MSNA（%）表示的MSNA反应不受手臂位置的影响。SHG期间的心率反应不受手臂抬高的影响，而平均血压和MSNA反应则因手臂抬高而增加（P<0.05）。在手臂抬高位置，SHG期的第二分钟（P<0.05）和PHGMI期（P<0.05）MSNA反应增加。总之，手臂抬高增加了对SHG和PHGMI的MSNA反应，表明肌肉代谢反射的幅度增加。
