As_2O_3引起LoVo细胞内钙离子浓度增高及意义

The increase of intracellular calcium induced by As_2O_3 in LoVo cells and its therapeutical significance

目的 观察LoVo细胞株经As2 O3 作用后细胞内钙离子浓度的改变并探讨其意义。方法 应用流式细胞仪观察亚二倍体细胞峰并检测LoVo细胞内的钙离子浓度。应用光镜、电镜观察As2 O3 对LoVo细胞生长的抑制作用、凋亡细胞形态和线粒体形态。结果 ①As2 O3 引起细胞内Ca2 +浓度升高 (P <0 .0 1) ,呈剂量依赖关系 (P<0 .0 1或 0 .0 5 ) ,在 2 .0 μmol/L组Ca2 +浓度最高 ;②在各时间段 ,对照组的Ca2 +浓度无变化 (P >0 .0 5 ) ,而经As2 O3 作用后Ca2 +浓度出现变化 (P <0 .0 1或 0 .0 5 ) ,在 2 0min时Ca2 +浓度均已增高 ,10h时增高最明显 ,至 2 4h ,0 .5 μmol/LCa2 +浓度回复到 2 0min时的水平 ,1.0和 2 .0 μmol/L组则低于 2 0min时的浓度 ;③As2 O3 抑制LoVo细胞生长 ;④LoVo细胞经As2 O3 作用后在光镜、电镜下出现细胞凋亡的形态学改变 ,并见线粒体肿大、嵴破坏或消失。流式细胞仪检测发现高浓度组凋亡细胞数高于对照组和低浓度组 (P <0 .0 1或 0 .0 5 )。结论 As2 O3 作用于LoVo细胞引起细胞内钙离子浓度增高 ,可能通过引起线粒体功能的改变而诱导细胞凋亡。

Objective To study the change of intracellular calcium level induced by As 2O 3 in LoVo cells and its significance. Methods The hypodiploid cell peak and the intracellular calcium level were determined by flowcytometry. The growth inhibition of LoVo cells and the morphology of apoptotic cells and mitochondria were studied under light microscope and electron microscope. Results (1)As 2O 3 induced an increase of intracellular calcium (P<0.01) in dose-dependent manner (P<0.01 or 0.05), with the calcium level highest in the 2.0 μmol/L test group. (2)The calcium level in control group was steady throughout the experiment. The As 2O 3-induced increase of calcium level was evident in 20 min, reached its peak at 10 h, and declined after 24 hours, approximating the calcium level at 20 min in the 0.5 μmol/L group and a little bit lower than that in the 1.0 and 2.0 μmol/L groups(P<0.01 or 0.05). (3)The growth of LoVo cells was inhibited by As 2O 3. (4)Microscopic studies showed As 2O 2 induced apoptotic and mitochondrial changes. Flowcytometry showed the frequency of apoptotic cells was proportional to the concentration of As 2O 3 in the culture fluid (P<0.01 or 0.05). Conclusion As 2O 3 may cause the intracellular calcium to increase in LoVo cells, affect the mitochondrial functions and induce apoptosis of the cells.