马桑毒内酯对大鼠海马锥体神经细胞内钙稳态的影响(英文)

Effect of coriamyrtin on calcium homeostasis in pyramidal neurons of hippocampus in rats

背景:神经元异常放电是癫痫的基本特征,这种异常放电的基础是细胞内外离子的跨膜运动,然而癫痫时是否存在钙离子内流,神经元膜上的钙通道是否开放还不清楚。目的:了解钙离子及钙通道在癫痫发病中的作用,探讨马桑毒内酯(coriamyrtiry,CM)调节神经细胞内钙稳态的机制。设计:培养的原代神经元随机分成:正常对照组;致痫组;尼莫地平组。利用激光扫描共聚焦显微镜技术观察胞内游离钙离子浓度的变化。地点和对象:以培养的Wistar乳鼠海马锥体神经元为靶细胞进行测试,实验在四川大学华西医院完成。干预:正常对照组不加任何条件;致痫组加入不同浓度的致痫剂CM。根据加入CM浓度的不同,又分为致痫10mL/L组、致痫20mL/L组、致痫40mL/L组、致痫80mL/L组。尼莫地平组同时加入CM(40mL/L)和尼莫地平。三组均培养24h后以Fluo-3进行负载,利用激光扫描共聚焦显微镜检测。主要观察指标:测量并记录锥体神经元和背景的荧光强度,以相对荧光强度代表游离钙离子值。结果:正常组神经细胞内Ca2+浓度为95.43±10.52,经致痫剂CM作用后,神经细胞内Ca2+浓度致痫10mL/L组为1299.87±68.53,致痫20mL/L组为1333.00±55.99,致痫40mL/L组为1315.33±55.73,致痫80mL/L组为1379.47±57.11,高于正常组(P<0.01),但其升高不呈剂量依赖性(P>0.05);

BACKGROUND:Abnormal discharge of neurons is the basic feature of epilepsy,which is based on the transmembrane movements of ions inside or outside cells.However,whether there is influx of Ca2+and the opening of the calcium channels on neuronal membrane in epilepsy are still unknown.OBJECTIVE:To investigate the role of Ca2+and calcium channels in the pathogenesis of epilepsy and to discuss the mechanism of Coriamyrtin(CM) in the regulations of intracellular calcium homeostasis. DESIGN:Primary cultured hippocampal pyramidal neurons were randomly allocated into control group, epileptic group, and Nimodipine group. The levels of intracellular free calcium ion (i)were tested by Laser Confocal Scanning Microscope techniques(LCSM).SETTINGS and MATERIALS:The primary cultured single pyramidal neurons of hippocampus in Wistar suckling rats were used as target cells in our study.This experiment was completed in West China Hospital affiliated to Sichuan University in Chengdu,China.INTERVENTION:No intervention was given to control group(group A).CM of different concentrations was given into epilepsy group(group B).According to the different concentration of CM,group B was divided into 10 mL/L of CM group (group B1),20 mL/L of CM group(group B2),40 mL/L of CM group(group B3),and 80 mL/L of CM group(group B4).40 mL/L of CM and Nimodipine were given simultaneously into Nimodipine group(group C).Neurons of these 3 groups were loaded by Fluo-3 after being cultured for another 24 hours following intervention.The intracellular Ca2+levels of neurons were detected by LCSM.MAIN OUTCOME MEASURES:Fluorescent intensity of pyramidal neurons and the background were measured and recorded. The relative fluorescent intensity represented the values of i.RESULTS:The i concentration in the control group was 95.43±10.52.After reacted with CM,a epilepsy inducer,the i concentration of group B1 was 129 9.87±68.53,group B2 was 133 3.00±55.99,group B3 was 131 5.33±55.73,and group B4 was 137 9.47±57.11,which were higher than normal group(P< 0.01),but with no dosedependent(p>05).Aftere management Of NimodiPine,a calcium channel blocker,CM stillcause an elevationof[CaZ十],(321 60士22 80)compared with thatofcontrol group(p<0.01),which was also significantly different from thatofgroupB(P<0.01).CONCLUSION:The oPening ofcalcium channels Plays an imPortarolein the pathogenesisd develoeni Of epilepsy.h may be one of theim-Portant aPProaches of Coriyrtin一induced ePilePsy to Promote the oPening ofcalcium channels