中文摘要：

目的研究神经节苷脂对As2O3体外干预的皮质神经元的保护作用及可能机制。方法 将人原代脑皮质神经细胞分为5组，空白对照组、5μmol·L^1As2O3干预组和5μmol·L^1As2O3如03加神经节苷脂50，100，200μg·L^-1组，Fluo-3／AM荧光探针标记皮质神经元胞浆钙（[Ca^2＋]i），激光共聚焦显微镜实时测定[Ca^2＋]i的变化。磷基转移法测定细胞膜和胞浆的蛋白激酶C（PKC）的活性。流式细胞仪检测细胞凋亡百分比。结果5μmol·L^-1的As2O3，作用3min，[Ca^2＋]．开始升高，并随时间延长逐渐明显，As2O3加神经节苷脂200μg·L^-1，作用9min，[Ca^2＋]i才开始升高，且程度远没有As2O3组明显。5μmol·L^-1的As2O3组的PKC活化程度明显高于As2O3加神经节苷脂组，以细胞膜相明显。24h凋亡率分别为：AsO3组78．5％，As2O3加神经节苷脂200μg·L^-1组13．5％。结论神经节苷脂抑制As2O3引起的皮质神经元的[Ca^2＋]i升高和PKC活化，抑制细胞凋亡。并通过对细胞膜靶点的保护来实现对神经细胞的保护作用，这进一步证明砷剂最初的作用靶点是细胞膜。

英文摘要：

OBJECTIVE To investigate the protective effect and the possible mechanism of ganglioside on cortex neuron lesions induced by arsenic trioxide. METHODS Five groups of human cortex neuron isolated from human cortex brain tissue and incubated in vitro were enrolled, including the control,5μmol·L^-1 As203 group, and 5μmol@L^-1 As2O3 ＋ ganglioside 50,100,200μg·L^-1 groups. The cytosolic calcium [Ca^2＋ ]i of cortex neurons were loaded by fluorescent probe Fluo-3/AM, the changes of [Ca^2＋ ]i were monitored by laser confocal microscopy in real time, the activation of protein kinase C on these changes was assayed by phosphorus radioisotope assay, the pereentage of apoptosis was analyzed by flow cytometry. RESULTS The [ Ca^2 ＋ ]i of cortex neurons began to increase at the 3th minute in 5 μmol· L^-1 As2O3 group,and at the 9th rain in As2O3 ＋ ganglioside group. Moreover, the degree of [Ca^2＋ ]i increasing was lower in As2O3 ＋ ganglioside group than that in As2O3 group. The PKC activation was higher in As2O3 group than that in As2O3 ＋ gangliosied group, especially the PKC in cell membrane. The apoptosis rates of cortex neurons was 78.5% in As2O3 group, and 13.5% in As2O3 ＋ gangliosied 200μg·L^-1 group after being incubated in vitro for 24h. CONCLUSION Ganglioside inhibites the increasing of [ Ca^2 ＋ ]i, the activation of PKC , and the apoptosis of cortex neurons is induced by arsenic trioxide concentration-dependently, and the preventive target is the neuron membrane. It shows that the neuron membrane is the initial target of As2O3 interference.