基于脊髓中枢敏化内热针干预慢性软组织疼痛机制研究

Effects of internal heat-type acupuncture needle intervention on chronic soft tissue pain based on central sensitization in the spinal cord

目的:基于脊髓中枢敏化机制探究内热针干预慢性软组织疼痛的机制。方法:将SD大鼠编号随机分为对照组、模型组、内热针组,每组15只。造模成功后对内热针组大鼠采用内热针治疗,在相关时间点对大鼠进行行为学观察,取材后采用Western Blot、RT-PCR及电生理的方法对L_(4-6)脊髓节段进行观察。结果:与模型组相比,内热针组大鼠L4-6脊髓节段NR1、NR2B、GluR1蛋白及mRNA的表达均明显降低,且未诱发出C纤维、Aδ纤维的长时程增强(long term potentiation,LTP),在强直刺激下的群峰电位幅度明显低于模型组。但内热针组大鼠促进了Aβ纤维LTP的诱发,在强直刺激下的群峰电位幅度明显高于模型组及对照组。结论:内热针治疗改善慢性软组织疼痛的机制可能与调节背根神经节和脊髓背角iGluRs的表达,抑制脊髓背角C纤维、Aδ纤维的LTP,促进Aβ纤维的LTP,缓解中枢敏化有关。

Objective:To explore the mechanism of internal heat-type acupuncture needle intervention on chronic soft tissue pain based on spinal cord central sensitization.Methods:Sprague-dawley(SD)rats were randomly divided into control group,model group,and internal heat-type acupuncture group(15 in each group).After successful modeling,the rats in the acupuncture group were treated with internal heat-type acupuncture,and the behavior of the rats was tested at the relevant time points.Western Blot,RT-PCR,and electrophysiological recording were used to observe the L4-6 spinal cord segments.Results:Compared with the model group,the expression of NR1,NR2B,GluR1 protein and mRNA in the L_(4-6) spinal cord segments of rats in the internal heat-type acupuncture group were significantly decreased,and the LTP of C and Aδ fibers was not induced,and the amplitude of group peak potential under the tonic stimulation was significantly lower than that in the model group.However,the induction of Aβfiber LTP was promoted,and the amplitude of group peak potential was significantly higher in the acupuncture group than that in model group and control group.Conclusion:The mechanism of internal heat-type acupuncture therapy to improve chronic soft tissue pain may be related to regulating the expression of iGluRs in the DRG and spinal dorsal horn,inhibiting LTP of C and Aδfibers in spinal dorsal horn,promoting LTP of Aβfibers,and reducing central sensitization.