毛果芸香碱致癎大鼠脑内胶质细胞源性神经营养因子及其受体α和Ret蛋白的表达

Expressions of GDNF, GDNFRα and Ret proteins in the brain of rats with seizures induced by pilocarpine

目的 :观察大鼠癫持续状态 (SE)后脑内胶质细胞原性神经营养因子 (GDNF)及其受体的动态表达。方法 :采用氯化锂—毛果芸香碱 (匹罗卡品 )诱发Wistar大鼠SE模型 ,根据不同时点进行分组 ,用抗生蛋白链菌素—过氧化物酶免疫组化法 (SP法 )观察皮质区和海马区的GDNF、GDNFRα和Ret的动态表达 ,并分析海马CA3区和门区GDNF阳性细胞与神经元变性坏死之间的关系。结果 :大鼠SE 1h后在皮质区和海马CA3区即有GDNF阳性细胞出现 ,1～ 3d达到高峰 ,7d接近正常水平 ;SE 2h后皮质区的GDNFRα阳性细胞达到高峰 ,在海马区极少见到 ;SE后在皮质区和海马CA3区均能见到Ret阳性细胞 ,6～ 8h最多 ;GDNF的表达水平与神经元变性坏死之间具有一定的关系。结论 :SE后的大鼠 ,其大脑皮质区和海马区的GDNF及其受体表达呈时间依赖性上调 ,GDNF、GDNFRα和Ret参与SE后神经损伤的反应应答过程 。

Objective: To observe the dynamic expression of GDNF and their receptors in the brain of rats after status epilepticus(SE). Methods: The lithium pilocarpine induced rat SE model was used. The expression patterns of GDNF, GDNFRα and Ret were observed dynamically with immunohistochemical technique,and the extent of neuron damage was assessed by HE stain. Results: (1)GDNF positive cells began to appear 2 hours after SE and reached the peak in 1 and 3 days, then decreased to the normal level;(2) GDNFRα positive cells in the cortex increased rapidly to the peak 2 hours after SE, and only few such cells were found in hippocampus;(3)Ret positive cells were found both in the cortex and hippocampus, with the maximum of expressions 6-8 hours after SE;(4)There were some connection between GDNF expression levels and extent of neurons damage. Conclusion: There exist time dependent upregulations of GDNF, GDNFRα and Ret protein in the cortex and hippocampus of rats after SE GDNF and their receptors involve in the response to neuron damage after SE, which might have the protective effect of neurons.