“穴位敏化池”的形成及其效应的生物学机制

Acupoint sensitization is a hot research topic in recent years, yet the local mechanism of acupoint sensitization needs to be further studied. In the present study, we propose a hypothesis: visceral disease induce acupoint sensitization at the surface of the body. Then "acupoint sensitization pool" forms in the sensitized acupoint, as the main feature of the acupuncture points in which inflammatory substance accumulation induced by neurogenic inflammation and/or sympathetic-sensory coupling. Acupuncture at sensitized acupoints suppresses the abnormal accumulation of local inflammatory mediators in the “acupoint sensitization pool”, then promotes the recovery of the disease. In the present study, chronic colitis is made by colonic perfusion of Tri-nitrobenzene (TNBS) in rats, technologies including behavior, infrared thermal imaging, immunohistochemistry, electrophysiology, biochemistry and molecular biology, Differential Proteomic have been used to investigate the formation and the laws of “acupoint sensitization pool”, then explore the local biological substance basis of “acupoint sensitization pool” in terms of neurogenic inflammation, sympathetic-sensory coupling and the inflammatory mediator, the marker proteins in the acupoint sensitization pool, and explore the effect of acupuncture at sensitized acupoints for rats with chronic colitis, and its correlation with the expression of local bioactive substances in the “acupoint sensitization pool”. The result of the present study will provide scientific basis for the interpretation of acupoint sensitization and its clinical application.

穴位敏化是近年来的研究热点，但是有关穴位敏化的局部机制有待深入研究。在本研究中我们提出以下假说：内脏疾病引起体表相关穴位敏化，局部形成“穴位敏化池”，表现为由神经源性炎性反应和交感-感觉耦联引起炎症物质聚积为主要特征的病理变化，针刺敏化穴则通过改变“穴位敏化池”的局部致炎物质的异常表达，促进疾病恢复。本项目以慢性结肠炎大鼠作为慢性内脏痛模型，采用行为学、激光多普勒与红外热成像、免疫组织化学、电生理学、生化与分子生物学，差异蛋白质组学方法等技术，研究内脏疾病引起的体表“穴位敏化池”的形成及规律；“穴位敏化池”中神经源性炎性和交感-感觉耦联及致炎相关物质的表达；以及与“穴位敏化池”形成相关的标志物蛋白；同时观察针刺敏化穴对慢性结肠炎大鼠的效应与 “穴位敏化池”局部生物活性物质表达的相互关系，以期揭示穴位敏化形成及其效应的生物学机制，为解释穴位敏化现象及其临床应用提供科学依据。

穴位敏化是近年来的研究热点，但是有关穴位敏化的局部机制有待深入研究。我们观察到：结肠炎造模后，大鼠出现明显的腹泻与便血，后肢躯体痛敏，结肠组织缺损，炎性粒细胞浸润等病理改变，同时结肠组织TNF-α、IL-1β、IL-6与KC/GRO含量显著升高。结肠炎模型大鼠伴随体表EB渗出点增多，T12-S1神经节段发生敏化，体表EB渗出区域以L2-5节段较为集中，其中足三里-上巨虚区域的EB渗出率为53.6%。EB渗出点表现出机械痛阈降低，温度升高，血流加快，激素含量(CORT)增加，促炎因子增加(TNF-α、IL-1β、IL-6与KC/GRO)的状态，（抗炎细胞因子IL-4、IL10含量变化不显著）形成穴位敏化池。同时结肠炎模型大鼠还可观察到背根节出现交感-感觉耦联的现象。感觉/交感神经可能共同参与了神经源性炎性反应。我们观察到，与对照区域相比，EB渗出区域P物质阳性神经纤维表达明显增多，肥大细胞脱颗粒释放tryptase，5-HT，而补体系统C3、CFB、PLG、FGB等差异蛋白可能介导了肥大细胞脱颗粒现象；同时血管周围CGRP阳性神经纤维与TH阳性神经纤维表达增多，对大鼠腹腔注射胍乙啶进行交感神经阻滞后EB渗出数量减少。结合之前行为学的研究结果，可以推断出：内脏疾病状态下，体表穴位出现敏化，而且感觉/交感神经共同参与穴位敏化的形成；而且敏化穴区IL-6、TNF-α与CORT的含量呈负相关，可能存在促炎/抗炎物质动态变化；敏化穴位局部炎症物质的改变与内脏炎症物质改变一致，这可能是穴位反应疾病的特性之一。.针刺敏化穴位可以起到良好的治疗作用。 结肠和ST 36的传入神经元重叠在L6 背根节。因此选用足三里穴位作为刺激部位，L6背根节作为观察重点。慢性结肠炎模型大鼠出现内脏痛敏和牵涉性体躯体痛敏，电针可以缓解以上异常痛敏。针刺可减轻结肠炎症、缓解内脏及躯体痛敏，其机制可能与抑制L6 DRG中的交感神经芽生相关。.通过本研究，我们提出：结肠炎模型大鼠体表出现穴位敏化，形成“穴位敏化池”，敏化池局部存在炎性物质的动态变化，针刺敏化穴位可以促进结肠炎的恢复。