电针对神经病理性疼痛大鼠的干预作用及其脊髓EAAs含量的影响

Interference Effect of Electroacupuncture on Neuropathological Pain and the Influence on Spinal EAAs Content in Rats

目的观察电针对神经病理性疼痛大鼠痛阈的作用以及脊髓兴奋性氨基酸含量的影响,探讨电针治疗神经病理性疼痛的机制。方法SD大鼠随机分为对照组、假模型组和造模组,采用大鼠坐骨神经分支选择性损伤(SNI)模型,造模组SNI术后选取造模成功的大鼠再随机分为模型组、电针组、假电针组。分别于SNI术前、术后第7天及第9天、第6次治疗后测定大鼠的机械痛阈和热痛阈。造模后第10天开始进行电针干预,电针"环跳"与"委中"穴,观察其对大鼠机械痛阈和热痛阈的影响,并通过脊髓微透析技术,应用柱前衍生法+HPLC荧光检测法检测大鼠脊髓兴奋性氨基酸的含量。结果SNI手术可以显著降低大鼠机械痛阈,模型组大鼠脊髓微透析液中Glu和Asp的含量较同时段对照组、假模型组有显著升高(P<0.05);电针组、假电针组脊髓微透析液中Glu和Asp含量与同时段模型组比较明显减少,差异具有统计学意义(P<0.05)(假电针组第2时段Glu除外),并且电针可以显著减轻SNI大鼠的机械痛敏状态。结论电针治疗神经病理性疼痛可能与降低脊髓兴奋性氨基酸含量有关。

Objective To investigate the effect of electroacupuncture on neuropathological pain and the influence on excitatory amino acid content of spinal cord in rats and explore the mechanism of electroacupuncture treatment of neuropathological pain.Methods SD rats were randomly allocated to control,sham model and model making groups.The rat spared nerve injury（SNI）model was used.Rats with a successful SNI operation were selected from the model making group and again randomly allocated to model,electroacupuncture and sham electroacupuncture groups.Mechanical pain threshold and thermal pain threshold were measured before the SNI operation,at seven and nine days after the operation and after the sixth treatment.Electroacupuncture intervention began at ten days after model making.Point Huantiao（GB 30）and Weizhong（BL 40）were electroacupunctured.The effects on mechanical pain threshold and thermal pain threshold were investigated in the rats.The excitatory amino acid content of rat spinal cord was measured by spinal microdialysis and precolumn derivatization ＋ HPLC-fluorescence detection.Results The SNI operation could obviously decrease rat mechanical pain threshold.The Glu and Asp contents of spinal dialysate were significantly higher during the same period in the model group of rats than in the control and sham model groups（P〈0.05）.During the same period,the Glu and Asp contents of spinal dialysate obviously decreased in the electroacupuncture and sham electroacupuncture groups compared with the model group and there was a statistically significant difference（P〈0.05）（except Glu during the second period in the sham electroacupuncture group）.Electroacupuncture could obviously reduce mechanical pain sensitivity in the SNI rats.Conclusion Electroacupuncture treatment of neuropathic pain may be related to decreasing the excitatory amino acid content of spinal cord.