大鼠坐骨神经切断后谷氨酰胺合成酶在脊髓后角内的表达变化

目的观察坐骨神经切断后不同时间点脊髓后角内谷氨酰胺合成酶（GS）的表达，探讨GS对神经元的保护机制。方法48只SD大鼠随机分为实验组（n=40）和对照组（n=8），其中实验组右侧坐骨神经切断，大鼠手术后分别存活1、3、7、14和21d（每时间点8只大鼠）。免疫组织化学方法检测脊髓后角内GS的表达变化。结果GS主要表达于神经胶质细胞胞体内。坐骨神经切断后GS表达开始增多，7d时GS表达最显著，之后GS表达下降，实验组各时间点与对照组相比具有统计学意义（P〈0．05），而实验组双侧后角相比无统计学意义（P〉0．05）。结论坐骨神经切断后脊髓后角内GS表达升高，这可能是GS对神经元保护作用的反应。

Changes of Glutamine Synthetase Expression in Posterior Horn of Spinal Cord after Sciatic Nerve Cut

Objective To observe the changes of glutamine synthetase（GS） expression in posterior horn of spinal cord at different time after sciatic nerve cut and approach the mechanism of GS protection to neuron. Methods Forty-eight SD 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 days,take out 8 rats in each time. The immunohistochemistry method was employed to detect GS expression change. Results GS mainly expressed in the body of glial cell. GS expression was increased at 1 day and the most predominance at 7 days after sciatic nerve cut,then GS expression descend. It had statistical significance by contrasting between 1,3,7,14.21 days of experiment group and normal control group（P〈0.05）,moreover it had no statistical significance by contrasting both posterior horn of experiment group （P〉0.05）. Conclusion The phenomenon that GS expression in posterior horn of spinal cord was elevatory is likely a reaction of GS to protect neuron after sciatic nerve cut.