山羊针刺内脏镇痛调节机制的研究

Acupuncture analgesia is not only the treasure of traditional Chinese medicine, but also one of the important reseach areas in neuroscience and surgery. Since acupuncture-induced analgesic effects in ruminants are superior over those in human or other species, there must exist a specific molecular mechanisms underlying acupuncture analgesia for ruminants. Previous related studies, mainly focusing on the acupuncture-elicited somatic analgesia, were rarely involved in acupuncture modulation of visceral pain. In the present program, the visceral pain of the goats is evoked through the injection of formalin into the ileum and the traction of a thread tying around the ileum adjacent to the cecum. The goats are stimulated with acupuncture applied to Zusanli points bilaterally for 30 min, one time every three days, for consecutive seven times. At the end of every acupuncture, the thread is drawn to elicit visceral pain which is reflected by the area under the curves of abdominal electromyogram and the behavioral response scores to pain. Acupucnture-induced visceral analgesia is appreciated. Six goats are randomly taken from each group, and slaughtered. The dynamic processes of the related active factors in the local intestinal tissue, neurotransmitters or neuromodulators in the ascending pathway and descending inhibitory system of visceral pain, proinflammary cytokines of glial cells, and their corresponding receptors are detected. The correlations of these factors with visceral pain are analyzed. Then the antagonists or agonists of the significantly changed factors are injected into the subarachnoid space or microinjected into the specific nuclei in order to verify their roles in the acupuncture-induced visceral analgesia. This project is conducive to completely elucidating the mechanisms underlying the acupuncture-induced visceral analgesia, to promote the development of the neuroscience and the application of acupuncture analgesic technique in the veterinary clinical practice.

针刺镇痛是传统中医学的瑰宝，是神经科学和外科学领域的重要研究方向之一。由于反刍动物针刺镇痛效果优于人和其它种属动物，反刍动物针刺镇痛存在特定的中枢分子调节机制。现有研究主要集中在针刺躯体镇痛方面，而针刺内脏镇痛调节机制的研究缺乏。本项目建立山羊肠道疼痛模型，针刺双侧足三里穴30 min，每3日1次，连续7次。每次电针后，牵拉肠壁作为疼痛刺激，以腹肌电图曲线下面积和疼痛行为反应积分为指标，评价针刺山羊的内脏镇痛效果；分别从各试验组中随机选取6只山羊宰杀，检测肠局部活性因子、疼痛上行传导和下行抑制通路中的神经递（调）质、胶质细胞中促炎因子及其相应受体水平，分析其与内脏疼痛的相关性。采用鞘内注射和神经核团微注射技术，将相关活性物质的拮抗剂或激动剂注入鞘内或核团，验证其在针刺内脏镇痛中的作用。该研究有助于全面揭示针刺内脏镇痛的调节机制，促进神经科学的发展和针刺镇痛技术在兽医临床中的推广应用。

针刺镇痛是传统中医学的瑰宝，是神经科学和外科学领域的重要研究方向之一。由于反刍动物针刺镇痛效果优于人和其它种属动物，反刍动物针刺镇痛存在特定的中枢分子调节机制。现有研究主要集中在针刺躯体镇痛方面，但针刺内脏镇痛调节机制的研究缺乏。. 本项目采用化学法诱导回肠末端肠壁慢性炎症，建立山羊肠道痛觉超敏模型。在此基础上，研究针刺对肠道局部、脊髓和脊髓上中枢痛觉调节相关核团（区域）中生物活性物质和下行痛觉调制系统的影响，以及针刺激活的镇痛相关中枢核团（区域）和耐受调节。本项目首次建立了山羊内脏牵拉疼痛模型和回肠炎性超敏模型，发现针刺显著抑制山羊脊髓N-甲基-D-天门冬氨酸型受体-2B（NMDAR-2B）、蛋白酶激活受体2（PAR-2）和降钙素基因相关肽（CGRP）的表达，增加谷氨酸转运体（EAAT2）表达；针刺降低山羊大脑、脊髓和肠壁组织内源性大麻素降解酶-脂肪酰胺水解酶（FAAH）和单酰基甘油酯酶（MAGL）的表达，增加内源性大麻素受体（CB1）的表达；显著抑制山羊脊髓、中脑导水管周围灰质、中缝大核和孤束核中IL6、pJAK2和pSTAT3的表达；增加中隔内侧核、弓状核、基底杏仁核、外侧伏核、腹外侧导水管周围灰质、蓝斑核、中缝大核、腺垂体和脊髓背角中c-Fos的表达；反复针刺诱导针刺耐受、脊髓谷氨酸转运体水平下降以及部分microRNAs（miR-148a-3p、miR-370-3p、let-7b-5p、miR-107-3p和miR-124-5p）的增加。结果表明针刺通过抑制脊髓或肠壁组织中FAAH、MAGL、NMDAR-2B、PAR-2和CGRP的表达水平，缓解内脏疼痛与超敏；通过降低IL6、pJAK2、pSTAT3或增加CB1在中枢下行痛觉调制通路中的表达水平，降低内脏超敏；针刺镇痛中枢神经调节环路为弓状核- 导水管周围灰质-中缝大核/蓝斑核-脊髓背角通路和下丘脑（腹内侧核、弓状核）-垂体通路；反复针刺降低脊髓谷氨酸转运体，并通过这些miRNAs诱导针刺耐受的形成。这些研究有助于神经科学的发展和针刺镇痛技术在兽医临床中应用。