Rea R F, Wallin B G
Department of Clinical Neurophysiology, Sahlgren's Hospital, University of Göteborg, Sweden.
J Appl Physiol (1985). 1989 Jun;66(6):2778-81. doi: 10.1152/jappl.1989.66.6.2778.
Nonhypotensive lower body negative pressure (LBNP) is reported to decrease forearm but not calf blood flow as measured by strain-gauge plethysmography. This suggests that unloading of cardiopulmonary receptors increases sympathetic outflow to arm but not to leg. To test this hypothesis we measured muscle sympathetic nerve activity (MSA) in the arm (radial nerve) and leg (peroneal nerve) simultaneously during LBNP. In eight healthy subjects, we measured heart rate, blood pressure, and radial and peroneal MSA during LBNP at 10 and 20 mmHg. There was no difference between radial and peroneal MSA at rest, and there were successive parallel increases of MSA in both nerves during LBNP at 10 and 20 mmHg. These data indicate that there are nearly identical increases of sympathetic outflow to the arm and leg during mild to moderate degrees of orthostatic stress.
据报道，通过应变片体积描记法测量，非低血压性下体负压（LBNP）会降低前臂血流量，但不会降低小腿血流量。这表明心肺感受器的卸载会增加交感神经向外周的输出，但对腿部没有影响。为了验证这一假设，我们在LBNP期间同时测量了手臂（桡神经）和腿部（腓总神经）的肌肉交感神经活动（MSA）。在8名健康受试者中，我们在10 mmHg和20 mmHg的LBNP期间测量了心率、血压以及桡神经和腓总神经的MSA。静息时桡神经和腓总神经的MSA没有差异，在10 mmHg和20 mmHg的LBNP期间，两条神经的MSA均连续平行增加。这些数据表明，在轻度至中度直立位应激期间，交感神经向外周的输出增加几乎相同。
