低频电针对选择性神经损伤大鼠神经痛维持期脊髓背角PKA-TRPV1通路及痛敏递质的干预作用

目的 探讨低频电针干预神经病理痛维持期脊髓背角（SCDH）蛋白激酶A（PKA）、辣椒素受体（TRPV1）通路的调控机制。 方法 将大鼠随机分为空白对照组、假手术组、模型对照组、电针干预组4组。采用坐骨神经分支选择性神经损伤（SNI）方法建立神经病理痛模型。电针干预取术侧足三里、昆仑穴，频率2Hz，每日1次，连续干预14d。检测大鼠术侧后足缩足阈值（PWT）、SCDH PKA和TRPV1以及降钙素基因相关肽（CGRP）和P物质（SP）水平。 结果 SNI模型大鼠术侧PWT下降（P<0.01），术侧SCDH PKA、TRPV1、CGRP、SP水平均上调（P<0.05）；2Hz电针可提高SNI模型大鼠PWT（P<0.01），降低术侧SCDH PKA、TRPV1、CGRP、SP水平（P<0.05）。 结论 低频电针能改善神经病理痛，可能与其下调SCDH PKA-TRPV1通路以及CGRP、SP痛敏递质水平有关。

The effects of low-frequency electroacupuncture on hyperalgesia PKA-TRPV1 signal pathway and neurotransmitters in the spinal cord of rats with neuropathic pain induced by spared nerve injury

Objective To explore the effect of low-frequency electroacupuncture (EA) on neuropathic pain induced by spinal nerve injury and its underlying mechanism. Methods Thirty-two male Sprague-Dawley rats were randomly divided into a normal group, a sham spared nerve injury (SNI) group, an SNI group and an SNI+EA group, each of 8. The rats in the SNI and SNI+EA groups were given SNI surgery, while those of the sham-SNI group only had the sciatic nerve and its branches exposed without any lesion. EA at 2 Hz was applied over the ipsilateral Zusanli and Kunlun acupoints daily for 14 days after the surgery. The ipsilateral paw withdrawal threshold (PWT) was measured, along with protein kinase A (PKA) levels in the dorsal horn of the spinal cord, calcitonin gene-related peptide (CGRP) and substance P (SP) levels along with transient receptor potential V1 (TRPV1). Results Compared to the normal group, the SNI groups all showed significant decreases in their PWTs on the affected side and significant increases in PKA, TRPV1, CGRP and substance P on the affected side. Compared to SNI group, the average ipsilateral PWT in the SNI+EA group increased significantly after EA treatment, while PKA levels, TRPV1, CGRP levels and SP expression all decreased significantly. Conclusion Electroacupuncture at low frequency can effectively relieve neuropathic pain, perhaps through down-regulation of PKA in the spinal cord and by decreasing pain hypersensitivity related to CGRP and SP.