匹罗卡品致大鼠癫痫持续状态后海马神经元凋亡的动态观察

目的 探讨癫痫持续状态(status epilepticus,SE)后海马细胞凋亡的发生及其与caspase-3表达的关系.方法 采用匹罗卡品诱发大鼠SE模型,用TUNEL染色和免疫组化技术检测海马神经元凋亡和caspase-3表达的动态变化.结果正常对照组大鼠海马未见TUNEL阳性细胞;SE后6 h,开始出现少量TUNEL阳性细胞;SE后72 h,达到高峰;SE后7 d,TUNEL阳性细胞开始减少.正常对照组大鼠海马可见少量caspase-3阳性表达;SE后6 h,大鼠海马caspase-3阳性表达增多,主要集中于CA1和CA3区;SE后48 h,caspase-3表达达到高峰;SE后72 h～7 d,caspase-3阳性染色细胞数开始减少;但仍显著多于对照组,差异有极显著意义(P＜0.01).结果 显示caspase-3表达分布与TUNEL染色基本一致,caspase-3表达高峰早于TUNEL所示凋亡细胞出现的高峰.结论 神经元凋亡参与了SE后海马神经元迟发性死亡过程并与caspase-3的激活有密切的关系.

Dynamic changes of apoptotic neuron in hippocampus after pilocarpine induced status epilepticus in rats

Objective To probe the occurrence of neuroal apoptosis in rats after status epilepticus(SE) and the relationship between neuron apoptosis and caspase-3 expression.Methods Rat model of SE was induced by intraperitoneal injection of 300 mg/kg pilocarpine in 20 male Wistar rats.Another 5 rats served as control.The apoptotic neuron was detected by TdT-mediated dUTP Nick End Labeling(TUNEL),and caspase-3 expression was observed by immunocytochemistry at 6~(th),48~(th),72~(th) h and 7~(th) d after SE induction.Results In control rats,TUNEL-positive neuron could not be found in hippocampus.The number of TUNEL-positive neuron began to increase at 6~(th) h after SE induction and peaked at 72~(th) h,began to decrease at 7~(th) d after SE induction.In control rats,there were few caspase-3 expression in hippocampus.The caspase-3 immunoreactivity began to increase at 6~(th) h after SE and peaked at 48~(th) h,especially in CA1 and CA3 region of hippocampus,began to decrease at 72~(th) h and dropped to normal level at 7~(th) d.The results indicated that the distribution of caspase-3 expression was consistent with the distribution of TUNEL-positive neuron.The peak of caspase-3 expression was earlier than that of TUNEL-positive neuron.Conclusion Neuron apoptosis participated in the process of delayed neuronal death in hippocampus after SE and was correlated with caspase-3 activation.