大鼠坐骨神经切断后谷氨酰胺合成酶在DRG内的表达变化

目的:观察坐骨神经切断后不同时间点背根神经节(DRG)内谷氨酰胺转化酶(GS)的表达变化。方法:48只SD大鼠随机分为实验组和正常对照组,其中实验组左侧为对照侧,右侧行坐骨神经切断。实验组大鼠分别存活1、3、7、14或21天。免疫组化方法检测DRG中GS的表达。结果:正常组DRG内GS主要表达于卫星细胞。坐骨神经切断1天后GS表达增加,明显高于正常组(P<0.05),3天时GS表达下降,7d时恢复正常。14天、21天时GS表达继续下降,明显低于正常组(P<0.05)。实验组手术侧和对照侧GS表达无显著性差异(P>0.05)。结论:坐骨神经切断后DRG内GS表达存在时空变化,这可能与坐骨神经切断后DRG内谷氨酸介导的兴奋性毒性有关。

Changes of Glutamine Synthetase Expression in Rat DRG after Sciatic Nerve Cut

Objective:To observe the changes of glutamine synthetase(GS)expression in dorsal root ganglion(DRG)at different time after sciatic nerve cut.Methods:48 rats were divided randomly into experiment group and normal control group.In the experiment group,right sciatic nerve was operation side and left sciatic nerve was control side.After sciatic nerve cut,rats survived for 1,3,7,14 and 21 day.We employ immunohistochemistry method to detect GS expression change.Results:GS mainly expressed at satellite cell of DRG in control group.GS expression was increasing at 1 day after sciatic nerve cut and apparently higher than that in the control group(P<0.05).Then,GS expression was decreasing at 3 day and recovering normal at 7 day.GS expression continued to decrease at 14 day and 21 day,and was lower than that of the control group apparently(P<0.05).There was no significant difference about GS expression between the operation side and the control side among experiment group(P>0.05).Conclusion:There was space-time changes of GS expression after sciatic nerve cut in DRG,which may be related with excitability toxicity mediated by glumatic acid after sciatic nerve cut in DRG.