丙戊酸对氯化锂-毛果芸香碱致癫(癎)大鼠海马神经元存活的影响

目的 探讨丙戊酸(VPA)对氯化锂-毛果芸香碱致癫(癎)大鼠神经元的保护作用.方法 出生35 d雄性Wistar大鼠分为空白对照组、癫(癎)模型组和VPA干预组,制作氯化锂-毛果芸香碱癫(癎)发作模型,VPA经口灌胃给药,每次350 mg·kg-1.VPA连续给药5 d后处死动物,取大鼠脑组织尼氏染色检测存活神经元,免疫组织化学检测脑源性神经营养因子(BDNF)蛋白和乙酰化H3组蛋白表达.结果 1.空白对照组海马形态学结构正常,细胞完整,神经元多呈三角形,核较大,胞质里可见深染尼氏小体;癫(癎)模型组大鼠海马CA1、CA3区可见神经元缺失、变性、坏死;尼氏小体数量较少,甚至出现尼氏小体溶解、消失;VPA干预组神经元坏死较少,改变较轻.2.癫(癎)模型组海马CA1区存活神经元数目显著少于空白对照组和VPA干预组;VPA干预组存活神经元数目较癫(癎)模型组增加(P<0.01),但仍少于空白对照组(P<0.01);癫(癎)模型组海马CA3区存活神经元数目显著少于空白对照组和VPA干预组(Pa<0.01);VPA干预组存活神经元数目较癫(癎)模型组增加(P<0.01),但仍少于空白对照组(P<0.01).3.癫(癎)模型组和VPA干预组海马CA1、CA3区BDNF蛋白的表达均较空白对照组高(P<0.05,0.01),但VPA干预组的表达高于癫(癎)模型组(P<0.05,0.01).4.VPA干预组CA1、CA3区乙酰化H3组蛋白表达较癫(癎)模型组和空白对照组均显著增加(Pa<0.01),癫(癎)模型组乙酰化H3组蛋白表达亦高于空白对照组(P<0.01).结论 VPA对氯化锂-毛果芸香碱致癫(癎)大鼠海马CA1、CA3区神经元具有保护作用;海马CA1 、CA3区乙酰化H3组蛋白表达增加,进而调控BDNF的表达增加,可能是VPA对癫(癎)后大鼠脑保护作用机制之一.

Influence of Valproate on Surviving Neurons in Hippocampus of Rats with Epilepsy by Lithium-Pilocarpine

Objective To explore the neuroprotective effect of valproate on neurons in hippocampus of epileptic model rat induced by lithium-pilocarpine.Methods Epileptic seizure model was induced in male Wistar rats 35 days after born with lithium-pilocarpine.The rats were divided into normal control group,seizures model group and vaploroic acid(VPA) intervention group,which were given valproate 350 mg·kg-1(6 times a day) for 5 days.All rats were sacrificed after 5 days,brain tissue were taken out,then surviving neurons were detected by Nissl′s staining,and the expression of brain derived neurotrophic factor(BDNF) and acetylated histone H3 were detected by immunohistochemistry.Results 1.The hippocampus formation in normal control group was normal.Most of neurons were triangulate,nucleolus was larger,and trachychromatic Nissl body was seen in cytolymph.The CA1,CA3 neurons in seizures model group were lost,degenerative and necrotic;the number of Nissl body was decreased,even dissolved and disappeared;pathological changes in VPA intervention group were less than seizures model group.2.The number of surviving neurons in hippocampal CA1 region in seizures model group was observably less than that in normal control group and VPA intervention group(P<0.01);the number of surviving neurons in VPA intervention group was increased than that in seizures model group(P<0.01),but decreased than that in normal control group(P<0.01);in hippocampus CA3 region,the number of surviving neurons in seizures model group was observably less than normal control group and VPA intervention group(Pa<0.01);the number of surviving neurons in VPA intervention group was increased than that in seizures model group(P<0.01),but decreasing than normal control group(P<0.01).3.In CA1,CA3 region,the optical density value of BNDF expression in seizures model group and VPA intervention group were more than that in normal control group(P<0.05,0.01);but the expression of BDNF in VPA intervention group was more than seizures model group(P<0.05,0.01).4.In CA1,CA3 region,the optical density value of acetylated histion H3 expression in VPA intervention group was remarkably increased than that in seizures model group(Pa<0.01) and normal control group(P<0.01),but the optical density value of acetylated histion H3 expression in seizures model group was more than that in normal control group(P<0.01).Conclusions VPA can protect hippocampus neurons of the epileptic rats induced by lithium-pilocarpine.The expression of acetylated histion H3 of hippocampus CA1,CA3 region increased,then regulated the expression of BDNF,which might be a mechanism of neuroprotective of VPA.