Alfonso-Rodriguez Jeimy, Wang Shuju, Zeng Xiaoling, Candiotti Keith A, Zhang Yanping
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, USA.
Hubei University of Chinese Medicine, Wuhan, Hubei, China.
Evid Based Complement Alternat Med. 2022 Aug 29;2022:7975803. doi: 10.1155/2022/7975803. eCollection 2022.
This study aimed to investigate the analgesic effect and mechanism of electroacupuncture (EA) in nicotine withdrawal-induced hyperalgesia rats.
Behavioral testing was conducted twice a week for 7 weeks during nicotine administration using von Frey filaments. Electroacupuncture at the bilateral "Zusanli" and "Taichong" points was applied daily for 3 days during nicotine withdrawal. Western blot analysis and immunohistology were used to determine expression levels of pain-related factors in the spinal cord and midbrain periaqueductal gray (PAG).
Behavioral tests showed that electroacupuncture had a significant analgesic effect on nicotine withdrawal-induced hyperalgesic rats. Western blot results demonstrated that, in hyperalgesic rats, the expressions of nicotinic acetylcholine receptors (subunits: nAChR 7, 4, or 2) decreased in the spinal cord, nAChR 7, and 2 decreased in PAG. The proinflammatory factor cyclooxygenase 2 (COX2) and the activated microglia (ionized calcium-binding adaptor molecule 1, Iba1 positive cells) increased in the spinal cord and PAG compared to controls. After electroacupuncture treatment, nAChR 7 and nAChR 2 expressions increased significantly, and COX2 and Iba1 expressions decreased in the spinal cord. Compared with the nonelectroacupuncture nicotine withdrawal group, electroacupuncture stimulation increased the expression of nAChR 7 and nAChR 4 in the PAG of rats with electroacupuncture. Immunohistochemical results confirmed that electroacupuncture reversed nicotine withdrawal-induced changes in nAChR 7 positive neurons and Iba1-positive microglia in the dorsal horn of the spinal cord.
Electroacupuncture treatment has an analgesic effect on nicotine withdrawal-induced pain in nicotine-dependent rats. The mechanism of analgesia of the electroacupuncture treatment relates to the increased expression of nAChR 7 and nAChR 2 proteins in the spinal cord, nAChR 7 in the PAG, and decreased expression of Iba1 and COX2 protein in the spinal cord.
本研究旨在探讨电针（EA）对尼古丁戒断诱导的痛觉过敏大鼠的镇痛作用及机制。
在尼古丁给药期间，每周使用von Frey细丝进行两次行为测试，持续7周。在尼古丁戒断期间，每天对双侧“足三里”和“太冲”穴进行电针治疗，持续3天。采用蛋白质免疫印迹分析和免疫组织学方法测定脊髓和中脑导水管周围灰质（PAG）中疼痛相关因子的表达水平。
行为测试表明，电针对尼古丁戒断诱导的痛觉过敏大鼠具有显著的镇痛作用。蛋白质免疫印迹结果显示，在痛觉过敏大鼠中，脊髓中烟碱型乙酰胆碱受体（亚基：nAChR 7、4或2）的表达降低，PAG中nAChR 7和2的表达降低。与对照组相比，脊髓和PAG中的促炎因子环氧化酶2（COX2）和活化的小胶质细胞（离子钙结合衔接分子1，Iba1阳性细胞）增加。电针治疗后，脊髓中nAChR 7和nAChR 2的表达显著增加，COX2和Iba1的表达降低。与非电针尼古丁戒断组相比，电针刺激增加了电针大鼠PAG中nAChR 7和nAChR 4的表达。免疫组织化学结果证实，电针逆转了尼古丁戒断诱导的脊髓背角nAChR 7阳性神经元和Iba1阳性小胶质细胞的变化。
电针治疗对尼古丁依赖大鼠尼古丁戒断引起的疼痛具有镇痛作用。电针治疗的镇痛机制与脊髓中nAChR 7和nAChR 2蛋白、PAG中nAChR 7的表达增加以及脊髓中Iba1和COX2蛋白的表达降低有关。
