Acupunct Electrother Res. 2002 ; 27(2): 119-27.

Acupuncture stimulation inhibits somato-renal sympathetic A- and C-reflexes in anesthetized rats.

Li WM, Wu GC, Arita H, Hanaoka K.

Department of Neurobiology, Medical Center of Fundan University (Former Shanghai Medical University), China.

Stimulation of peripheral nerve afferent for example tibial nerve by a strong electrical stimulation (rectanfular wave with 20V amplitude; pulse duration of 0.5 ms, 0.3 pulses/sec) can evoke a discharge of the somato-sympathetic reflex which is recorded on the efferent of renal sympathetic nerve. The component of the somato-sympathetic reflex can be divided into two parts: one is related to the transmission of the myelinated afferent fibers with a short lantency (41+/-2 ms) and is defined A-reflex, the other is related to the transmission of the unmyelinated afferent fibers with a long latency (210+/-13 ms) and is defined C-reflex. In the present study, an acupuncture needle (diameter 0.34 mm) was inserted into the hind limbs of the rat, dorsolaterally at the area of acupoint: huantiao (GB30), at a depth of 4-5 mm and was twisted right and left twice every second during recording the somato-renal sympathetic reflex. It was found that acupuncture on the huantiao acupoint significantly inhibited both A- and C-reflexes. There was no different inhibition of the A- and C-reflexes by acupuncture on the right or left side. However acupuncture on the fore limbs of the rat dorsolaterally at the area of acupoint: quchi (LI11) showed no effect on neither A- nor C-reflexes. These results suggest that acupuncture at the same spinal segment of the acupoint inhibits the somatorenal sympathetic reflex.