基于MC活化-PAR2-CGRP环路探讨电针治疗PI-IBS模型大鼠内脏高敏感的作用机制

类胰蛋白酶是肠黏膜肥大细胞活化脱颗粒的重要标志之一，其受体2（protease-activated receptor2，PAR2）能促进CGRP及P物质释放，诱发内脏高敏感。我们前期研究证实电针能够减少PI-IBS大鼠肠黏膜肥大细胞（MC）活化数目及类胰蛋白酶含量，降低CGRP及P物质表达。基于既往研究我们发现MC活化、PAR2和CGRP具有相互作用，其中PAR2在三者之间发挥关键性的调控。本研究采用三硝基苯磺酸（TNBS）建立PI-IBS内脏高敏感动物模型，借助PAR2激动剂，通过电镜、Western-Blot、Real-time PCR和激光共聚焦等方法，检测电针后结肠黏膜MC形态，PAR2蛋白、CGRP等物质含量及其mRNA在结肠和脊髓部位的变化,阐述电针通过调节PAR2的表达，对MC活化-PAR2-CGRP环路形成良性调控，从而缓解内脏高敏感，为针灸临床治疗IBS提供科学依据。

Tryptase is an important sign of mast cell degranulation , and its receptor 2 (protease-activated receptor2, PAR2) can contribute to increasing expression of CGRP and substance P, which induce visceral hypersensitivity of IBS. Our previous study have showed that acupuncture can decrease the number of mast cells and the content of tryptase in the intestinal mucosa with PI-IBS.Then we also have found that electro-acupunture also reduce the expression of CGRP at the same time. Based on previous experimental studies, we found that out there are mutual interaction between MC degranulation , PAR2 and CGRP .Especially PAR2 plays a important role . Therefore, the study use the method of trinitrobenzene sulfonic acid to build PI-IBS visceral hypersensitivity in animal models, after treating mice with electro-acupuncture or applying PAR2 agonists(PAR2-AP), we observe the expression of PAR2,SP and CGRP and other substances in colonic mucosa and dorsal root ganglia neurons through the method of Real-time PCR, Western-blot technique and so on.Through the evaluation of expression changes in PAR2,SP , CGRP and other substances as well as visceral hypersensitivity changes.We expect to explore the electro-acupuncture role on PAR2 in reducing visceral hypersensitivity in PI-IBS is by regulating the cycle of MC degranulation-PAR2-CGRP , to provide a reliable theoretical basis for clinical electro-acupuncture treatment of PI-IBS.