亚砷酸钠对DNA损伤修复的抑制实验  

STUDY ON THE INHIBITION OF DNA DAMAGE-REPAIR BY SODIUM ARSENITE

作　　者：刘蜀坤[1] 李娜[1] 叶丛茂[2] 王玲[1] 张遵真[1] 

机构地区：[1]四川大学华西公共卫生学院环境卫生教研室,成都610041 [2]成都市第七人民医院

出　　处：《现代预防医学》2008年第18期3492-3494,3497,共4页Modern Preventive Medicine

基　　金：国家自然科学基金资助项目(30571535)

摘　　要：[目的]探讨砷化物的毒作用机制。[方法]MTT实验检测亚砷酸钠对A549细胞的细胞毒性,彗星实验观察其单独作用时细胞的DNA损伤效应;然后以3因素析因设计的彗星实验分析亚砷酸钠对苯并(a)芘(BaP)所致的DNA损伤效应的影响。[结果]随着亚砷酸钠浓度的增加,细胞存活率下降;在彗星实验中,当亚砷酸钠单独作用时,各浓度组细胞拖尾率与阴性对照组相比无统计学差异;联合BaP染毒,当BaP浓度一定时,亚砷酸钠浓度越高细胞拖尾率也越高,显著增强了BaP所致的DNA损伤效应,且亚砷酸钠预作用24h后观察到的DNA损伤较同时染毒和BaP预作用24h观察到的DNA损伤更为严重。[结论]亚砷酸钠不直接损伤DNA,能降低细胞DNA损伤的修复,从而增强另一种基因毒物所致的DNA损伤作用。[Objective] To explore the mechanisms involved in toxicity of arsenic. [Methods] MTT assay was used to detect the cytotoxieity of sodium arsenite on human lung adenocarcinoma A549 cells. Comet assay was applied to measure the DNA damage of cells treated with sodium arsenite alone or combined with benzo （a） pyrene. Then factorial design with three factors was applied to analyze the effect of sodium arsenite on the DNA damage-repair induced by benzo （a） pyrene. [ Results ] The cell viability decreased with the increasing of sodium arsenite concentration. When only exposed to sodium arsenite, the comet cell rate in all groups was not found significant difference when compared with the negative control （P 〈 0.05）; When combined with benzo （a） pyrene, the comet cell rate increased with the concentration of benzo （a） pyrene at the certain concentration of BaP, and significantly increase the DNA damage induced by benzo （a） pyrene. Furthermore, pre-treatment of A549 ceils with NaAsO2 for 24h could induce more serious DNA damage than the other two sequences. [ Conclusion ] NaAsO2 couldn＇t induce DNA damage directly. But it might increase the DNA damage induced by another mutagen through inhibiting DNA damage-repair.

关 键 词：亚砷酸钠 DNA损伤修复 彗星实验 

分 类 号：R114[医药卫生—卫生毒理学]