Okada A, Naito M, Ariizumi M, Inaba R
Department of Public Health, School of Medicine, Kanazawa University, Japan.
Eur J Appl Physiol Occup Physiol. 1991;62(5):324-31. doi: 10.1007/BF00634967.
Multi-unit sympathetic activity was recorded at elbow level from median nerve fascicles supplying glabrous skin of the left hand in five healthy subjects. The resultant vasomotor responses accompanying the neural activity were monitored by simultaneous recordings of skin blood flow using the laser doppler method and skin temperature in the innervation zones. No significant change in sympathetic activity was observed during handgrip exercise of the right hand under a constant gripping force of 2 kg. Subjects maintained the same gripping force of the right hand during exposure in random order to local vibration and/or noise, each type of exposure lasting 5 min with intervals of 20 min. A two-peaked significant increase in outflow from sympathetic nerves was observed during local exposure of the right hand to vibration with a frequency of 60 Hz and an acceleration of 50 m.s-2, followed by a postexposure period which revealed a relative suppression of sympathetic nerve activity and a significant increase in blood flow. Noise at 100 dB(A) showed only an initial effect on skin sympathetic nerve activity (SSA), whereas when combined with local vibration at 60 Hz, a pronounced increase in neural activity was noticed, indicating a combined effect of vibration and noise. These results from direct recordings of SSA suggest a sympathetic vasomotor reflex mechanism triggered by local vibration stimuli to the hand.
在五名健康受试者中，从供应左手无毛皮肤的正中神经束在肘部水平记录多单位交感神经活动。通过使用激光多普勒方法同时记录皮肤血流和神经支配区域的皮肤温度，监测伴随神经活动产生的血管运动反应。在右手以2千克的恒定握力进行握力运动期间，未观察到交感神经活动有显著变化。受试者在随机顺序暴露于局部振动和/或噪声时，右手保持相同的握力，每种暴露持续5分钟，间隔20分钟。在右手局部暴露于频率为60赫兹、加速度为50米·秒⁻²的振动期间，观察到交感神经流出量出现双峰显著增加，随后的暴露后阶段显示交感神经活动相对抑制，血流显著增加。100分贝(A)的噪声仅对皮肤交感神经活动(SSA)有初始影响，而当与60赫兹的局部振动相结合时，会注意到神经活动明显增加，表明振动和噪声有联合作用。这些直接记录SSA的结果表明，手部局部振动刺激触发了交感血管运动反射机制。
