丙戊酸钠对大鼠海马神经元癫痫样放电后细胞外信号调节激酶磷酸化水平的影响

摘要

目的 细胞外信号调节激酶(extracellular signal-regulated kinase 1/2,ERK1/2)参与癫痫的发生,但其与抗癫痫药物之间的关系不明确,文中旨在观察丙戊酸钠对大鼠海马神经元癫痫样放电后磷酸化ERK1/2(p-ERK1/2)的影响.方法 取24h内新生Wistar大鼠,雌雄不拘,迅速断头取脑.建立神经元癫痫样放电模型,将神经元分为空白对照组和丙戊酸钠组,量效实验中,于神经元癫痫样放电前30min时加入不同浓度的丙戊酸钠(50mg/L、75mg/L、100mg/L),运用免疫荧光技术测定p-ERK1/2在不同浓度时的表达;时效实验中,分别于癫痫样放电前30min,放电后0min、30min、2h和6h加入50mg/L丙戊酸钠,采用 Wester blot观察p-ERK1/2的变化.结果 量效实验中,不同浓度的丙戊酸钠均能降低ERK1/2的磷酸化水平,且无显著性差异.时效实验中,于放电前30min时加入丙戊酸钠对ERK1/2的磷酸化水平抑制最明显,与以后各时间点间都有显著性差异.结论 海马神经元癫痫样放电后ERK1/2被过度持久的激活,在早期小剂量有效浓度的丙戊酸钠能显著抑制此反应中ERK1/2的磷酸化水平.%Objective Extracellular signal-regulated kinase l/2(ERKl/2) plays a role in the occurrence of epilepsy , but the mechanism of the involvement of ERK1/2 and its association with antiepileptic drugs remain unclear . The aim of this study is to investi -gate the effects of valproate sodium on ERK 1/2 phosphorylation (p-ERKl/2) after hippocampal neuronal epileptiform discharge in rats. Methods The epileptiform discharge model of the neuron was established in female and male neonate Wistar rats by rapid de -capitation. The neurons were divided into a blank control and a valproate sodium group , the latter incubated with valproate sodium at 50, 75 and 100 mg/L 30 min before epileptiform discharge in the concentration response experiment, and the expression of p-ERKl/2 at different concentrations detected using immunofluorescence technique . In the time-response experiment, the neurons were incubated with valproate sodium at 50 mg/L 30 min before and 0 min, 30 min, 2 h and 6 h after epileptiform discharge. Changes in p-ERKl/2 were observed by Western blot. Results In the concentration response experiment, valproate sodium decreased the level ofrnp-ERKl/2, with no significant difference among different concentrations. In the time-response experiment, the inhibitory effect of valproate sodium on p-ERKl/2 was the most significant at 30 min before epileptiform discharge , as compared with the other time points . Conclusion ERK1/2 could be excessively and persistently activated after epileptiform discharge of neurons , and low-dose effective concentration of valproate sodium could suppress p-ERKl/2 at an earlier time of epileptiform discharge of neurons .