氯化锂-匹罗卡品致痫大鼠海马结构中CLC-2、CLC-3氯通道表达变化的研究

目的 研究ClC-2、ClC-3氯通道在氯化锂-匹罗卡品大鼠慢性癫痫模型中分布和表达的变化,探讨其在癫痫发作病理机制中的作用.方法 Wistar大鼠采用随机数字表法分成致痫组(60只)与对照组(20只),其中致痫组根据处死及处理时间又分为24h组、14d组与30d组,每组20只.致痫组复制氯化锂-匹罗卡品大鼠慢性癫痫模型,在发作后24h、14d、30d时,分别予以:(1)免疫组化染色,观察ClC-2、ClC-3氯通道蛋白在海马表达的分布情况及其致病后不同时点的吸光度(A)值的变化;(2)RT-PCR,观察ClC-2、ClC-3氯通道mRNA在致痫后不同时点的变化.结果 (1)与对照组比较,致痫后14d至30d,致痫组免疫反应阳性神经元数和A值明显减少和降低,差异有统计学意义(P<0.05);ClC-2 mRNA表达降低,差异有统计学意义(P<0.05).(2)与对照组比较,致痫组致痫后24 h,海马CA1、CA3及齿状回各层ClC-3免疫反应阳性神经元数和A值明显增加和升高,差异有统计学意义(P<0.05);ClC-3氯通道mRNA表达明显增加,差异有统计学意义(P<0.05).结论 癫痫慢性期的发作和ClC-2氯通道的减少有关.

Expressional changes of CLC-2 and CLC-3 chloride channel in the hippocampus of rats with lithium-pilocarpine-induced epilepsy

Objective To investigate the distribution and expression changes of voltage-gated chloride channel CLC-2 and CLC-3 in rat models with lithium-pilocarpine-induced chronic epileptic,and discuss the significance of these changes in epileptic pathogenesis.Methods Eighty Wistar rats were randomly divided into status epilepticus(SE,n=60)and control(n=20)groups and rats in the SE group were assigned to 3 subgroups according to the different sacrificed times(24 h,14 d and 30 d).Rat models with chronic epileptic in the SE group were induced by lithium-pilocarpine.Immunohistochemistry was employed to observe the changes of voltage-gated chloride channel CLC-2 and CLC-3 in rat's hlppocampal formation different time points after seizure.The mRNA changes of chloride channel CLC-2 and CLC-3 at different time points after seizure were observed by RT-PCR.Results Compared with those in the control group,the quantity of CLC-2 immune positive neurons and the average optical density in the SE group decreased obviously 14 and 30 d after seizure;so was the mRNA expression of CLC-2(P<0.05).Compared with the control group,the SE group showed obviously increased quantity of CLC-3 immune positive neurons and optical density at each area of the hippocampus 24 h after seizure;so was the mRNA expression of CLC-3(P<0.05).Conclusion Seizures at chronic phase have relation with the decreased expressions of CLC-2.