β-淀粉样蛋白_(25-35)片段致大鼠嗜铬细胞瘤细胞损伤的钙离子机制  

Calcium mechanism in neurotoxicity induced by soluble Aβ_ (25-35) on pheochromocytoma cell lines

作　　者：邵梅[1] 陈生弟[1] 刘振国[1] 刘军[1] 

机构地区：[1]上海第二医科大学附属瑞金医院神经科,200025

出　　处：《中华神经科杂志》2002年第4期207-209,共3页Chinese Journal of Neurology

基　　金：上海市科委自然科学基金资助项目 ( 99ZB14 0 19)

摘　　要：目的　探讨水溶性Aβ2 5 35损伤体外培养大鼠嗜铬细胞瘤 (PC12 )细胞的钙离子机制。方法　应用二甲基噻唑二苯基四唑溴盐 (MTT)分析法研究细胞活性的改变 ,应用激光共聚焦显微镜观察细胞内钙离子浓度的相对变化。结果　用MTT分析法发现 10 μmol/LAβ2 5 35、10 μmol/LAβ2 5 35+5μmol/L硝苯地平、10 μmol/LAβ2 5 35+10 μmol/L硝苯地平 3个实验组的细胞活性较对照组分别下降34.5 %、2 5 .1%和 11.0 % ;预加 10 μmol/L硝苯地平可有效地阻止Aβ2 5 35所致的细胞活性下降。 0 .1、1、10、2 0和 30 μmol/L不同浓度的Aβ2 5 35可致胞内钙离子浓度分别升高约 6 .4%、6 .4%、6 2 .2 %、6 9.3%和10 7.5 % ,呈现剂量依赖性。预加Aβ2 5 351min后可以增强氯化钾升高细胞内钙离子的程度。上述两种作用依赖于细胞外钙离子 ,同时可被L 电压门控钙通道特异性阻断剂硝苯地平所拮抗。结论　水溶性Aβ2 5 35作用早期可以破坏神经细胞的钙离子稳态 ,使细胞对外界生理性或病理性刺激敏感度增强 ,容易遭受损伤。Objective To investigate the calcium mechanism involved in the Aβ 25-35-induced neurotoxicity.Methods PC12 cells viability was detected by using MTT assay. Relative change of intracellular calcium concentration was measured by laser confocal microscope.Results MTT assay showed that the cell viability of the three groups (10 μmol/L Aβ 25-35?10 μmol/L Aβ 25-35+5 μmol/L nifedipine?10 μmol/L Aβ 25-35+10 μmol/L nifedipine) was decreased by 34.5%, 25.1% and 11.0%,as compared with the control group. 10 μmol/L nifedipine could protect PC12 cells from Aβ 25-35-induced damage. Aβ 25-35 of different concentration (0.1 μmol/L, 1 μmol/L, 10 μmol/L, 20 μmol/L and 30 μmol/L) resulted in the elevation of intracellular calcium (about 6.38%, 6.42%, 62.2%, 69.3% and 107.5%) with a dose-dependent manner. Potassium (5 mmol/L, 15 mmol/L and 30 mmol/L) could increase the intracellular calcium after one minute pretreatment of different concentration Aβ 25-35. Both above mentioned actions were sensitive to the medium calcium and were antagonized by nifedipine, a L-voltage-gated calcium channel antagonist.Conclusion Soluble Aβ 25-35 may damage the neuronal calcium homeostasis in early stage and make neurons more vulnerable to physiological or pathological stimuli.

关 键 词：淀粉样Β蛋白 钙离子机制 PC12细胞 阿尔茨海默病 动物实验 

分 类 号：R749.1[医药卫生—神经病学与精神病学]