低频电针对SNL大鼠早期神经痛DRG p-TRPV1、CGRP的抑制作用

目的]探讨低频电针干预早期神经痛对背根神经节（dorsal root ganglion,DRG）辣椒素受体（Transient receptor potential vanilloid type 1,TRPV1）磷酸化与痛敏相关神经肽降钙素基因相关肽（calcitonin gene-related peptide,CGRP）与P物质（substance P,SP）的抑制作用。方法]SD大鼠随机分为正常组、假手术组、模型组与电针组,每组8只。模型组采用脊神经结扎（spinal nerve ligation,SNL）的方法制作大鼠神经痛模型。电针组采用2 Hz电针治疗,选取患侧＂足三里＂、＂昆仑＂穴,连续3d。检测D1、D3大鼠术侧后足缩腿阈（Paw withdrawal threshold,PWT）,D3 L5 DRG p-TRPV1、CGRP、SP水平。结果]SNL模型大鼠早期即出现自发性疼痛,PWT显著下降（P〈0.001）,L5 DRG p-TRPV1水平升高（P〈0.001）,CGRP水平升高（P〈0.05）,SP水平下降（P〈0.05）。SNL假手术组大鼠PWT没有显著变化。2 Hz电针能提高SNL模型大鼠的PWT（P〈0.001）,降低L5 DRG p-TRPV1水平（P〈0.05）与CGRP水平（P〈0.01）,对SP水平没有显著影响。结论]早期神经痛与DRG p-TRPV1、CGRP水平升高有关。低频电针能下调DRG p-TRPV1与CGRP水平,改善早期神经痛。

Inhibition of DRG p-TRPV1,CGRP during Early Neuropathic Pain in Rats Suffered From Spinal Nerve Ligation by Electroacupuncture with Low Frequency

Objective] To investigate the inhibitive effects of electroacupuncture（EA） with low frequency on DRG p-TRPV1,CGRP and SP during early neuropathic pain.Methods] SD rats were randomly divided into Normal,Sham spinal nerve ligation（SNL）,SNL,and SNL ＋EA groups,8 animals per group.Rat neuropathic pain model was made by right L5 SNL in SNL group.2 Hz EA was administered at ipsilateral points Zusanli and Kunlun for consecutive 3 days in SNL ＋EA group.D1 and D3 PWT,D3 L5 DRG TRPV1 phosphorylation（p-TRPV1）,CGRP and SP levels were measured.Results] Rats in Sham SNL group had no obvious change in PWT,while rats in SNL group developed spontaneous pain and had a significant reduction in PWT（P〈0.001）.L5 DRG p-TRPV1 and CGRP levels were increased（P〈0.001,P〈0.05）,while SP level was reduced（P〈0.05） in SNL rats.2 Hz electroacupuncture up-regulated SNL rats PWTs（P〈0.001）,reduced L5 DRG p-TRPV1 and CGRP levels（P〈0.05,P〈0.01）,and had no significant effect on L5 DRG SP level.Conclusion] Early neuropathic pain was associated with up-regulation of DRG p-TRPV1 and CGRP.Electroacupuncture with low frequency could alleviate early neuropathic pain through reducing DRG p-TRPV1 and CGRP levels.