基于嗅觉通路探讨艾烟对膝骨性关节炎大鼠镇痛效应的分子机制

The effects of moxibustion therapy mainly include heat, light, smoke, and the combined effect of these factors. At present researches on moxa smoke are mainly limited to its chemical composition,pharmacological effects and so on. There are less in-depth studies of therapeutic effect of moxibustion and moxibustion mechanism action. Smell is the only human sense that associated with the external environment and which act directly on the brain--many odorous molecules can act directly on the brain through the olfactory pathway. Therefore, we hypothesized that: moxa smoke may be involved in the effect of central system regulation via the olfactory pathway. This project observe some changes of rats: the pain response, gait, the knee joint range and the change of the swellin by applying different concentrations moxa smoke to intervention knee osteoarthritis model in rats.This study apples in techniques such as micro-dialysis, fluorescence quantitative PCR and immunohistochemical techniques to observe the change of some indicators of model rats: changes of the content of 5 - HT and DA in the knee joint cavity effusion, the expression of the hypothalamus ENK and beta EP, the expression of substance P of articular cartilage.And to explore the analgesic effect of moxa smoke for knee osteoarthritis model rats. This study also observes the change of the analgesic effect of moxa smoke for knee osteoarthritis model rats after apophysis mamillaris lesion and olfactory epithelium lesion. The study analyses the effect of olfactory pathway in the analgesic effect of moxa smoke for knee osteoarthritis model rats in order to provide further experimental support for the clinical application of moxibustion.

艾灸疗法主要包括了热、光、烟因素及其综合作用。目前对艾灸烟效应的研究主要限于化学成分、药理作用等方面，对其治疗效应及作用机制缺乏深入的研究。嗅觉是人类唯一与外部环境相联系并直接作用于脑的感觉，许多气味分子可以通过嗅觉传导通路直接作用于脑。因此，我们提出假说：艾烟可能通过嗅觉通路的吸入，参与艾灸的中枢镇痛调控过程。本项目通过不同浓度艾烟干预膝骨性关节炎模型大鼠，观察大鼠疼痛反应、步态、膝关节活动范围以及肿胀情况，应用在体微透析采样、荧光定量PCR、免疫组化等技术观察模型大鼠关节液5-HT、DA含量变化、下丘脑ＥＮＫ、β-ＥＰ的表达、关节软骨P物质的表达，探讨不同浓度艾烟对膝骨性关节炎模型大鼠的镇痛效应；并观察嗅上皮损毁、嗅球损毁后艾烟对膝骨性关节炎模型大鼠镇痛效应的变化，分析嗅觉通路在艾烟对膝骨性关节炎模型大鼠镇痛效应中的作用，为艾灸的临床应用提供进一步的实验支持。

本实验通过模拟艾灸诊室的空气质量安全性检测确定了艾烟浓度分级,通过观察不同浓度艾烟吸入对大鼠呼吸系统的影响、不同浓度艾烟对膝骨性关节炎（KOA）模型大鼠关节局部效应的影响、嗅球摘除后艾烟吸入对KOA大鼠脑内神经递质分泌的影响以及艾烟对嗅觉障碍大鼠镇痛物质的影响，初步发现中、高浓度艾烟持续熏灸会引起血浆、肺泡灌洗液和肺组织匀浆液中IL -1β和TNF-α表达的增高，引起肺和支气管组织产生较明显的病理变化；大鼠在不同浓度艾烟环境干预后，关节液中的TNF-α、BAX 和 IL-1βmRNA相对表达量降低，Bcl-2 mRNA相对表达量增多；较高浓度艾烟环境可以使脑组织内的5-HT、DA、NE和Ach含量显著增多；嗅球摘除后， DA和Ach的含量显著降低。嗅上皮损毁后艾烟对脑β-EP、ENK和脊髓SP的表达的调节作用受到一定影响。结果表明长期处于中、高浓度艾烟环境中可能会引起肺和支气管产生炎性改变，但呼吸功能未见改变；不同浓度艾烟环境下，KOA模型大鼠膝关节软骨损伤恢复较好，炎性反应减轻，细胞凋亡减少，具有一定的治疗意义，但考虑到本次实验过程中未能排除艾灸“热”的作用，本次实验结果不能完全说明是单纯艾烟的作用；艾烟可以通过嗅觉通路影响单胺类神经递质的释放和镇痛物质的表达，进而发挥在疼痛抑制环节的作用，但具体作用通路有待更加深入研究。本研究从嗅觉通路的角度，初步探明艾烟的安全性以及对膝骨性关节炎模型大鼠的效应，为进一步深入探明艾烟的安全性及有效性奠定基础。