经TRPV1/TRPA1⁃cGMP信号通路探究推拿对minor CCI模型大鼠背根神经节镇痛启动机制

Exploring the analgesic initiation mechanism of tuina on the dorsal root ganglion in minor chronic constriction injury model rats via the TRPV1/TRPA1⁃cGMP signaling pathway

目的探究三法三穴推拿手法对minor CCI模型大鼠的镇痛启动机制。方法将56只SD大鼠随机分为8组,即正常组、假手术组、模型1组、模型2组、推拿1组、推拿2组、推拿1+TRPV1拮抗剂组和推拿2+TRPA1拮抗剂组。模型组、推拿组和推拿+拮抗剂组建立minor CCI模型。推拿组和推拿+拮抗剂组在造模后7 d进行1次三法(点法、拨法、揉法)三穴(殷门穴、承山穴、阳陵泉穴)干预,模型组与假手术组进行抓握束缚,正常组不予干预。干预结束后各组先后进行机械缩足反射阈值(MWT)和热缩足反射潜伏期(TWL)测试不同性质痛觉的变化;采用硝酸还原酶法观察各组造模侧DRG中NO含量,ELISA、Western blot、qPCR等方法观察各组造模侧DRG内TRPV1/TRPA1⁃NO⁃cGMP⁃PKG信号通路蛋白、基因表达的变化情况。结果与模型组比较,行为学检测显示推拿1组、推拿2组MWT、TWL均有不同程度的延长;推拿1组、推拿2组、推拿1+TRPV1拮抗剂组、推拿2+TRPA1拮抗剂组DRG内TRPV1、TRPA1、NO、sGCβ、cGMP、PKG1的表达量均明显降低。结论推拿干预1次后即可有效改善周围神经损伤引起的温度觉、机械痛觉过敏症状;推拿可通过TRPV1/TRPA1⁃NO⁃cGMP⁃PKG信号通路发挥即刻镇痛和持续镇痛作用。

Objective To explore the analgesic initiation mechanism of three⁃manipulation and three⁃acupoint tuina in model rats with minor chronic constriction injury(CCI).Methods Fifty⁃six SD rats were divided randomly into eight groups:normal group,sham group,model 1 group,model 2 group,tuina 1 group,tuina 2 group,tuina 1+transient receptor potential vanilloid⁃1(TRPV1)antagonist group,and tuina 2+transient receptor potential ankyrin 1(TRPA1)antagonist group.The model,tuina,and tuina+antagonist groups were established with minor CCI models.The tuina and tuina+antagonist groups received the three⁃method three⁃point intervention(point method,dial method,kneading method,Yinmen point,Chengshan point,Yanglingquan point)7 days after modeling.The model and sham groups were subjected to grasping restraint,and the normal group received no intervention.After the respective interventions,each group was tested for changes in mechanical withdrawal threshold(MWT)and thermal withdrawal latency(TWL)to detect different types of pain.The nitric oxide(NO)content of the dorsal root ganglion(DRG)was determined by the nitrate reductase method,and changes in protein and gene expression levels of components of the TRPV1/TRPA1⁃NO⁃cGMP⁃protein kinase G(PKG)signaling pathway in the DRG of each group were determined by enzyme⁃linked immunosorbent assay,Western blot,and qPCR.Results Compared with the model group,MWT and TWL were prolonged in the tuina 1 and tuina 2 groups.Expression levels of TRPV1,TRPA1,NO,soluble guanylate cyclase⁃β,cGMP,and PKG1 in the DRG were significantly decreased in the tuina 1,tuina 2,tuina 1+TRPV1 antagonist,and tuina 2+TRPA1 antagonist groups.Conclusions Tuina can effectively improve the symptoms of thermal and mechanical hyperalgesia caused by peripheral nerve injury after one⁃time intervention.Tuina can exert immediate and continuous analgesic effects via the TRPV1/TRPA1⁃NO⁃cGMP⁃PKG signaling pathway.