目的 研究亚砷酸钠( sodium arsenite)对大鼠胰岛β细胞株INS-1(INS-1细胞)的凋亡作用及其机制.方法 将INS-1细胞暴露于不同浓度的亚砷酸钠,首先进行噻唑蓝(MTT)试验,并用荧光分光光度计测定INS-1细胞线粒体膜电位及溶酶体膜电位的吸光度(A)值;并于亚砷酸钠作用后,应用荧光显微镜和流式细胞仪观察并检测INS-1细胞的凋亡情况.结果 经亚砷酸钠作用后,INS-1细胞的活性明显下降,且细胞活性随着亚砷酸钠剂量的升高而降低;24h后,细胞线粒体膜电位荧光值明显下降,且随着亚砷酸钠剂量的增加而降低,差异有统计学意义(P<0.01);48h后,细胞溶酶体膜电位荧光值明显上升,且随着亚砷酸钠剂量的增加而升高,差异有统计学意义(P<0.01);72 h后,荧光显微镜下观察细胞,出现凋亡,随着亚砷酸钠剂量的增加,凋亡的细胞也随之增多,镜下呈亮蓝色,胞核固缩、裂解为碎块出现凋亡小体和核碎裂,部分染色质出现浓缩状态;流式细胞仪检测结果,经亚砷酸钠处理后,凋亡的细胞明显增多,且随着亚砷酸钠剂量的增高,凋亡细胞数量也随之增多.结论 亚砷酸钠通过线粒体-溶酶体途径诱导大鼠胰岛β细胞株INS-1凋亡.
Objective To study mechanism of the apoptosis of rat pancreas islet β cell strain (INS-1cells) induced by sodium arsenite.Methods INS-I cells were exposed to sodium arsenite at the different concentrations.MTr assay was used to detect the viability of INS-1 cells.The potentials on mitochondrial membrane and lysosome membrane of INS-1 cells were determined with the fluorescence spectrophotometer.The apoptotic levels of INS-1 cells exposed to sodium arsenite were observed by a fluorescence microscope and flow cytometry.Results After exposure to sodium araenite,the viability of INS-1 cells significantly decreased with the doses of sodium arsenite.At 24 h after exposure,the OD values of the mitochondrial membrane potentials declined observably with the doses of sodium arsenite (P<0.01).At 48 h after exposure,the OD values of the lysosome membrane potentials significantly increased with the doses of sodium arsenite (P<0.01).At 72 h after exposure,the apoptotic cells were observed under a fluorescence microscope and enhanced with the doses of sodium arsenite.The apoptosis cells with light blue,karyopyknosis,karyorrhexis,apoptotic body and chromatin concentration appeared.The results detected with flow cytometry indicated that after exposure,the apoptotic INS-1 E cells significantly increased with the doses of sodium arsenite.Conclusions The sodium arsenite can induce the apoptosis of INS-1 cells through the mitochondria-lysosome pathway.