Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan.
Evid Based Complement Alternat Med. 2012;2012:636848. doi: 10.1155/2012/636848. Epub 2012 Nov 13.
Although pain is a major human affliction, our understanding of pain mechanisms is limited. TRPV1 (transient receptor potential vanilloid subtype 1) and TRPV4 are two crucial receptors involved in inflammatory pain, but their roles in EA- (electroacupuncture-) mediated analgesia are unknown. We injected mice with carrageenan (carra) or a complete Freund's adjuvant (CFA) to model inflammatory pain and investigated the analgesic effect of EA using animal behavior tests, immunostaining, Western blotting, and a whole-cell recording technique. The inflammatory pain model mice developed both mechanical and thermal hyperalgesia. Notably, EA at the ST36 acupoint reversed these phenomena, indicating its curative effect in inflammatory pain. The protein levels of TRPV1 and TRPV4 in DRG (dorsal root ganglion) neurons were both increased at day 4 after the initiation of inflammatory pain and were attenuated by EA, as demonstrated by immunostaining and Western blot analysis. We verified DRG electrophysiological properties to confirm that EA ameliorated peripheral nerve hyperexcitation. Our results indicated that the AP (action potential) threshold, rise time, and fall time, and the percentage and amplitude of TRPV1 and TRPV4 were altered by EA, indicating that EA has an antinociceptive role in inflammatory pain. Our results demonstrate a novel role for EA in regulating TRPV1 and TRPV4 protein expression and nerve excitation in mouse inflammatory pain models.
虽然疼痛是人类的一大痛苦，但我们对疼痛机制的理解是有限的。TRPV1（瞬时受体电位香草酸亚型 1）和 TRPV4 是两种与炎症性疼痛相关的关键受体，但它们在 EA（电针）介导的镇痛中的作用尚不清楚。我们向小鼠注射角叉菜胶（carra）或完全弗氏佐剂（CFA）以建立炎症性疼痛模型，并通过动物行为测试、免疫染色、Western blot 和全细胞记录技术研究 EA 的镇痛作用。炎症性疼痛模型小鼠表现出机械性和热痛觉过敏。值得注意的是，ST36 穴位的 EA 逆转了这些现象，表明其对炎症性疼痛的疗效。免疫染色和 Western blot 分析表明，在炎症性疼痛开始后的第 4 天，DRG（背根神经节）神经元中 TRPV1 和 TRPV4 的蛋白水平均升高，而 EA 则减弱了这种升高。我们验证了 DRG 的电生理特性，以确认 EA 改善了周围神经过度兴奋。我们的结果表明，EA 改变了 AP（动作电位）阈值、上升时间和下降时间，以及 TRPV1 和 TRPV4 的百分比和幅度，表明 EA 在炎症性疼痛中具有镇痛作用。我们的结果表明，EA 在调节 TRPV1 和 TRPV4 蛋白表达和神经兴奋方面在小鼠炎症性疼痛模型中具有新的作用。
