电针颈夹脊穴对神经根型颈椎病模型大鼠伤害性感觉神经元兴奋性的影响研究

Effect of Electro-Needling Cervical Jiaji Acupoints on Excitability of Nociceptive Sensory Neurons in Rats with CSR

目的:观察电针颈夹脊穴对神经根型颈椎病(CSR)模型大鼠伤害性感觉神经元兴奋性的影响。方法:将48只SD大鼠随机分为空白组,假手术组,模型组,电针组,共4组,每组12只。除空白组外,其余3组大鼠均通过结扎左侧C7背根神经节远端神经根制备CSR模型(假手术组采用同样手术方法但不结扎神经根)。空白组不做任何干预,假手术组、模型组、电针组均从造模后第15天开始干预,连续干预14 d,同时观察并记录各组大鼠热痛阈值的变化;采用ELISA法检测4组大鼠C6-C7脊髓节段谷氨酸、前列腺素、一氧化氮(NO)的表达;采用Western blot法和实时荧光定量PCR法检测4组大鼠C7背根神经节降钙素基因相关肽(CGRP)、腺苷酸环化酶(AC)、人钙离子通道抗体(VGCC)蛋白和基因的表达。结果:干预前,假手术组大鼠较空白组相比,热痛阈值差异无统计学意义(P>0.05),模型组大鼠与假手术组相比,热痛阈值明显降低(P<0.05),连续干预14 d后,电针组大鼠与模型组对比,热痛阈值显著升高(P<0.05);连续干预14 d后,ELISA结果显示,模型组大鼠与假手术组相比,脊髓组织谷氨酸、前列腺素、NO表达均明显升高(P<0.05),电针组与模型组相比,脊髓组织谷氨酸、前列腺素、NO表达均明显降低(P<0.05);蛋白和基因结果显示,模型组大鼠与假手术组相比,背根神经节CGRP、AC、VGC蛋白及基因表达均明显升高(P<0.05),电针组与模型组相比,背根神经节CGRP、AC、VGC蛋白及基因表达均明显降低(P<0.05)。结论:电针颈夹脊穴对CSR大鼠具有镇痛作用,其镇痛机制可能与调控伤害性感觉神经元的兴奋性,抑制谷氨酸、前列腺素、NO、CGRP、AC、VGCC的表达有关。

Objective:To observe the effects of electro-needling cervical Jiaji points on the excitability of nociceptive sensory neurons in rats with cervical spondylotic radiculopathy(CSR),and to explore the analgesic mechanism of electro-needling cervical Jiaji points in treatment of CSR.Methods:48 SD rats were randomly divided into the blank group,the sham operation group,the model group and the electro-acupuncture(EA)group,with 12 rats in each group.CSR model was established by ligating the distal nerve root of the left C7 dorsal root ganglion,the sham operation group used the same operation method but did not ligate the nerve root.Rats in the blank group received no intervention,the sham operation group,the model group and the EA group all started the intervention from the 15th day after modeling and last continuous 14 days.The changes of thermal pain threshold were observed and recorded in each group.The expressions of glutamate,prostaglandin and NO in spinal cord segment of C6-C7 were detected by ELISA method.The protein and mRNA expressions of CGRP,AC and VGCC in C7 dorsal root ganglion were detected by Western blot and real-time PCR,respectively.Results:Before intervention,there was no significant difference in the thermal pain threshold between the sham operation group and the blank group(P>0.05),but the heat pain threshold in the model group was significantly lower than that in the sham operation group(P<0.05);after 14 days of continuous intervention,the heat pain threshold in the EA group was significantly higher than that in the model group(P<0.05).After 14 days of continuous intervention,the results of ELISA showed that the expressions of glutamate,prostaglandin and NO in spinal cord ganglion were significantly higher in the model group than those in the sham operation group(P<0.05);compared with those in the model group,the expressions of glutamate,prostaglandin and NO in the spinal cord ganglion were significantly lower in the EA group(P<0.05).The protein and mRNA expressions of CGRP,AC and VGC in spinal cord ganglion were significantly higher in the model group than those in the sham operation group(P<0.05);compared with those in the model group,the protein and mRNA expressions of CGRP,AC and VGC in spinal cord ganglion were significantly lower in the EA group(P<0.05).Conclusion:Electro-needling cervical Jiaji points has analgesic effects on CSR rats,and its analgesic mechanism may be related to regulating the excitability of nociceptive sensory neurons and inhibiting the expressions of glutamate,prostaglandin,NO,CGRP,AC and VGCC.