Yu Xiangdi, Zhang Fangxiang, Chen Bingning
Department of Anaesthesiology, Guizhou Provincial People's Hospital, Guiyang, China.
Acupunct Med. 2017 Apr;35(2):142-147. doi: 10.1136/acupmed-2016-011063. Epub 2016 Oct 4.
Acupuncture and related techniques are used worldwide to alleviate pain; however, their mechanisms of action are still not fully understood. In the present study, we investigated the effect of transcutaneous electrical acupuncture point stimulation (TEAS) at different frequencies in a chronic constriction injury (CCI) model of neuropathic pain in rats.
CCI was induced by ligating the common sciatic nerve, which produced neuropathic pain. 18 male Sprague-Dawley rats with CCI were randomly divided into three groups (n=6 each) that remained untreated (CCI group) or received TEAS at high frequency (CCI+TEAS-H group) or TEAS at low frequency (CCI+TEAS-L group). Rats in the CCI+TEAS-H group received high frequency stimulation (6-9 mA, 100 Hz) at GB34/GV26/ST36; those in the CCI+TEAS-L group received low frequency stimulation (6-9 mA, 2 Hz) at the same points. Rats in the control group had the same electrodes applied but received no stimulation. All three groups were subjected to behavioural studies after treatment. Expression of μ opioid receptors (MORs) in the L3-L5 dorsal root ganglion (DRG) was determined by immunofluorescence staining and Western blotting after treatment.
Compared with the untreated CCI group, both mechanical allodynia and thermal hypergesia were significantly attenuated, and MOR expression in the DRG was significantly increased by low frequency TEAS treatment at GB34/GV26/ST36 (p<0.05). In contrast, no significant differences were observed between the CCI and CCI+TEAS-H groups.
The use of low frequency TEAS significantly mitigated neuropathic pain in this rat model, and its analgesic effect is likely mediated by upregulation of MOR expression in the DRG.
针刺及相关技术在全球范围内用于缓解疼痛；然而，其作用机制仍未完全明确。在本研究中，我们在大鼠神经性疼痛的慢性压迫损伤（CCI）模型中，研究了不同频率的经皮穴位电刺激（TEAS）的效果。
通过结扎坐骨神经诱导CCI，从而产生神经性疼痛。18只患有CCI的雄性Sprague-Dawley大鼠被随机分为三组（每组n = 6），分别为未治疗组（CCI组）、接受高频TEAS组（CCI + TEAS - H组）或接受低频TEAS组（CCI + TEAS - L组）。CCI + TEAS - H组的大鼠在GB34/GV26/ST36接受高频刺激（6 - 9 mA，100 Hz）；CCI + TEAS - L组的大鼠在相同穴位接受低频刺激（6 - 9 mA，2 Hz）。对照组大鼠应用相同电极但不接受刺激。治疗后，对所有三组进行行为学研究。治疗后，通过免疫荧光染色和蛋白质印迹法测定L3 - L5背根神经节（DRG）中μ阿片受体（MORs）的表达。
与未治疗的CCI组相比，低频TEAS在GB34/GV26/ST36治疗可显著减轻机械性异常性疼痛和热痛觉过敏，并且DRG中MOR的表达显著增加（p < 0.05）。相比之下，CCI组和CCI + TEAS - H组之间未观察到显著差异。
在该大鼠模型中，低频TEAS的使用显著减轻了神经性疼痛，其镇痛作用可能是通过上调DRG中MOR的表达介导的。
