惊厥持续时间对惊厥后海马神经元凋亡及其对早期事件变化的影响

目的观察持续惊厥（SC）后大鼠海马神经元凋亡及线粒体膜电位（Δψm）、细胞色素C（cytC）含量变化及惊厥持续时间对上述指标的影响。方法采用氯化锂-匹罗卡品法诱发幼年Wistar大鼠SC发作,分别制备惊厥持续发作30min和3h的SC模型。于SC30min后3、6和12h及1d,SC3h后3h、6h及1d时,采用流式细胞仪检测海马神经元凋亡及线粒体Δψm、cytC含量的变化,比较惊厥持续时间与三者的相关性。结果SC30min后凋亡细胞及线粒体Δψm、cytC含量分别较正常对照组显著改变,6h时线粒体Δψm、cytC含量变化达峰值,凋亡则于12h时达峰值。SC3h后凋亡细胞及线粒体Δψm、cytC含量均显著高于SC30min后相同观察时间点。经偏相关参数分析,不同惊厥持续时间与海马神经元凋亡及线粒体Δψm、cytC含量变化均呈正相关（P均〈0.05）。结论严重惊厥可引起大鼠海马神经元凋亡及线粒体Δψm、cytC含量的变化;惊厥持续时间越长,凋亡及其凋亡早期事件的变化越明显。

Effect of duration of convulsion state on neuronal apoptosis and early apoptotic events in hippocampus of rats

OBJECTIVE: To explore the influence of duration of convulsion state (SC) on neuronal apoptosis, mitochondrial membrane potential (Deltapsim) and cytochrome C (cyt C) release in hippocampus in Wistar rats after SC. METHODS: SC lasting for 30 minutes or 3 hours was induced by intraperitoneal injection of lithium chloride and pilocarpine. Rats were sacrificed at 3, 6, 12 hours and on 1 day after 30 minutes SC and at 3, 6 hours and on 1 day after 3 hours SC. The apoptosis, mitochondrial Deltapsim and intracellar cyt C were determined with flow cytometry, and the correlation with SC duration was compared. RESULTS: The proportion of apoptotic cells, the decrease in mitochondrial Deltapsim and the release of intracellar cyt C significantly changed at 30 minutes after SC. The peak level of apoptosis was seen at 12 th hour after SC and that of mitochondrial peaked at 6 th hour after SC in apoptosis and the two early apoptotic events, respectively. Compared with the same time point after 30 minutes SC, the levels of apoptosis and the two early apoptotic events after 3 hours SC were much higher. The neuronal apoptosis and the two early apoptotic events in hippocampus after SC showed positive correlation with the duration of SC in partial correlation analysis (all P<0.05). CONCLUSION: Severe seizure could induce the changes in neuronal apoptosis and the early apoptotic events in hippocampus after SC. The longer the duration of SC is, the more serious change in apoptosis and early apoptotic events are.