摘要
目的:检测人胚肺二倍体成纤维细胞WI38受到60Coγ射线照射后线粒体DNA(mtDNA)的相对含量和线粒体功能的改变;探讨γ射线照射后细胞线粒体的变化规律。方法:四氮唑盐(MTT)比色法测细胞活力;采用竞争PCR法测定mtDNA的相对含量;荧光染料R123和TMRM分别标记,流式细胞仪测定线粒体膜电位的变化;酶标分光仪测定线粒体呼吸链氧化酶NADH氧化酶反应2min内活性变化。结果:与正常细胞相比,60Coγ射线照射后,照射组细胞明显肿胀,变短,边缘不整齐,排列紊乱,数量减少;细胞活力(0.359±0.02)明显低于正常组(0.598±0.03,P<0.05);线粒体膜电位约下降为原来的50%;NADH氧化酶活性也降低,最大反应速度由48.93μmol/(mg·min)降为27.80μmol/(mg·min);以核18SrDNA为内参照,照射组mtDNA相对含量为(1.680±0.082),明显高于正常组的(1.296±0.077)。结论:γ射线照射后,WI38细胞mtDNA相对含量的增高可能是线粒体功能下降的一种代偿性反应。
Objective：To investigate changes of mhochondrial DNA（mtDNA） relative content and function in human embryonic lung diploid cell line WI-38 irradiated by ^60Co γ-ray. Methods： Cell viability was assayed by MTT; mtDNA relative content was measured by a competitive polymerase chain reaction（PCR） method. Cells were marked by fluoresent R123 and TM-RM, and mhochondrial membrane potential was measured by flow cytometry. NADH oxidase activity was measured by Absorbance Microplate Reader within 2 min. Results： Compared with normal cells,cells irradiated by ^60Co γ-ray became short,obvi-ously tumid, irregularly arrayed,and reduced in number. The viability of the irradiated cells（0. 359±0.02） was obviously lower than that of the normal cells（0. 598±0.03）;their mitochondrial membrane potential declined to half of the normal level； and their NADH oxidase activity also decreased, with the maximal reaction speed decreasing from 48.93μmol/（mg·min） to 27.80μmol/（mg · min）. Taking 18S rDNA as the internal control, mtDNA relative content of the irradiated cells（1. 680±0. 082）was higher than that of the normal cells（ 1. 296±0. 077）. Conclusion： The increased mtDNA relative content in cells irradiatedby ^60Co γ-ray may be one of the compensatory mechanisms for decreased mitochondrial function.
出处
《第二军医大学学报》
CAS
CSCD
北大核心
2005年第8期885-887,共3页
Academic Journal of Second Military Medical University
基金
国家自然科学基金(30171030
30472175)
中国博士后科学基金(2004036014).
