<p>Electroacupuncture decreases Netrin-1-induced myelinated afferent fiber sprouting and neuropathic pain through μ-opioid receptors</p>

作者：Hongping Li, Wen Su, Yang Shu, Xiao-Cui Yuan, Li-Xue Lin, Teng-fei Hou, Hong-Chun Xiang, He Zhu, Xue-Fei Hu, Pan Li, Jing-Nan Wu, Xian-Fang Meng, Hui‐Lin Pan, Cai-Hua Wu, Man Li · 发表于：Journal of Pain Research · 年份：2019 · DOI：10.2147/jpr.s191900 · 被引用次数：31 · 研究领域：Axon Guidance and Neuronal Signaling、Pain Mechanisms and Treatments、Pain Management and Placebo Effect

Purpose: We determined whether electroacupuncture (EA) reduces Netrin-1-induced myelinated primary afferent nerve fiber sprouting in the spinal cord and pain hypersensitivity associated with postherpetic neuralgia (PHN) through activation of μ-opioid receptors. Methods: PHN was induced by systemic injection of resiniferatoxin (RTX) in rats. Thirty-six days after RTX injection, a μ-opioid receptor antagonist, beta-funaltrexamine (β-FNA) or a κ-opioid receptor antagonist, nor Binaltorphimine (nor-BNI), was injected intrathecally 30 mins before EA, once every other day for 4 times. Mechanical allodynia was tested with von Frey filaments. The protein expression level of Netrin-1 and its receptors (DCC and UNC5H2) were quantified by using western blotting. The myelinated primary afferent nerve fiber sprouting was mapped with the transganglionic tracer cholera toxin B-subunit (CTB). Results: Treatment with 2 Hz EA at “Huantiao” (GB30) and “Yanglingquan” (GB34) decreased the mechanical allodynia at 22 days and the myelinated primary afferent nerve fiber preternatural sprouting into the lamina II of the spinal dorsal horn at 42 days after RTX injection. Also, treatment with 2 Hz EA reduced the protein levels of DCC and Netrin-1 and promoted the expression of UNC5H2 in the spinal dorsal horn 42 days after RTX injection. Furthermore, the μ-opioid receptor antagonist β-FNA, but not the κ-opioid receptor antagonist nor-BNI, reversed the effect of EA on neuropathic pain caused by RTX. In ...