低频电针对脊神经结扎大鼠痛敏化的干预作用

摘要

Objective To investigate the effect of electroacupuncture with low frequency on pain sensitization of neuropathic pain rats, and the possible mechanism of regulating peripheral pain sensitization. Methods Rat neuropathic pain model was established with the right L5 spinal nerve ligation. Zusanli (ST36) and Kunlun (BL60) were selected for electroacupuncture intervention. Mechanical allodynia, and the levels of stransient receptor potential vanilloid type 1 (TRPV1) and substance P (SP) in ipsilateral L5 and L4 dorsal root ganglion (DRG) were tested. A further validation experiment with TRPV1 agonist 6'-IRTX was carried out. Results Rats suffered from L5 spinal nerve liga-tion showed obvious pain sensitization. The levels of TRPV1 in ipsilateral L4 DRG and SP in ipsilateral L5 DRG were significantly elevated. Electroacupuncture with low frequency significantly relieved pain sensitization, and suppressed TRPV1 and SP increase. 6'-IRTX intraperito-neally administered significantly counteracted the anti-pain sensitization action of electroacupuncture with low frequency. Conclusion Elec-troacupuncture with low frequency is effective on neuropathic pain by intervening pain sensitization, which may be related to the regulation of DRG TRPV1 and SP.%目的：观察低频电针对脊神经结扎神经病理痛大鼠模型痛敏化的干预作用，探讨其可能的外周痛敏化调节机制。方法建立大鼠L5脊神经结扎模型，电针足三里和昆仑穴，观察大鼠痛觉超敏反应，运用Western blotting法检测L4、L5背根神经节(DRG)辣椒素受体(TRPV1)与P物质(SP)水平，采用TRPV1激动剂6'-IRTX进行验证。结果脊神经结扎大鼠出现明显的痛敏化反应，术侧L4 DRG TRPV1和L5 DRG SP水平升高(P<0.05)；低频电针能减轻模型大鼠的痛敏反应，抑制TRPV1、SP水平上升(P<0.05)。6'-IRTX腹腔注射能拮抗低频电针的抗痛敏化作用。结论低频电针可减轻痛敏化，发挥对神经病理痛的治疗作用，其机制可能与其有效调控DRG TRPV1和SP有关。