Wallin B G, Victor R G, Mark A L
Department of Clinical Neurophysiology, Sahlgren's Hospital, University of Göteborg, Sweden.
Am J Physiol. 1989 Jan;256(1 Pt 2):H105-10. doi: 10.1152/ajpheart.1989.256.1.H105.
Simultaneous microneurographic recordings were made of muscle sympathetic activity (MSA) in the radial and the peroneal nerves of seven healthy subjects during 2-min static handgrip (30% of maximal voluntary contraction) followed by 2 min of forearm ischemia induced by arterial occlusion. At rest sympathetic burst frequency was similar in both nerves, but relative burst strengths differed between the two neurograms, suggesting that sympathetic outflows to arm and leg were not identical. Both radial and peroneal MSA were unchanged during the first minute of handgrip and increased to a similar degree during the second minute. Thus previously reported differences in vascular resistance between forearm and calf during static handgrip cannot be explained by differences in MSA to arm and leg muscles. During forearm ischemia after handgrip, peroneal MSA remained at the same level as during the second minute of handgrip but there was a further increase of radial MSA. This shows that stimulation of chemosensitive endings in forearm muscles induces differentiation of sympathetic neural outflow to muscles in the leg and the contralateral arm.
对7名健康受试者的桡神经和腓神经进行了同步微神经图记录，记录内容为肌肉交感神经活动（MSA）。先进行2分钟的静态握力试验（最大自主收缩的30%），随后通过动脉闭塞诱导2分钟的前臂缺血。静息时，两条神经的交感神经爆发频率相似，但两个神经图的相对爆发强度不同，这表明支配手臂和腿部的交感神经输出并不相同。在握力试验的第一分钟，桡神经和腓神经的MSA均未改变，在第二分钟时均增加到相似程度。因此，先前报道的静态握力试验期间前臂和小腿血管阻力的差异，无法用支配手臂和腿部肌肉的MSA差异来解释。在握力试验后的前臂缺血期间，腓神经的MSA保持在握力试验第二分钟时的水平，但桡神经的MSA进一步增加。这表明，前臂肌肉中化学敏感末梢的刺激会导致交感神经向腿部和对侧手臂肌肉的输出产生分化。
