镍冶炼烟尘致NIH/3T3细胞DNA损伤的实验研究

目的 研究镍冶炼烟尘致DNA损伤作用.方法 采用单细胞凝胶电泳（SCGE）技术,检测2份镍冶炼烟尘对小鼠NIH/3T3细胞的DNA损伤.结果 相同染毒时间内,随着染毒剂量（除样品2中50.0μg/ml剂量染毒24 h组）加大,细胞拖尾率增高,DNA断裂程度在4 h达到高峰,分别为35.5%、69.7%、85.2%、41.3%、75.7%、89.2%.各受试物在相同剂量下,染毒4 h时均较染毒2 h和染毒24 h细胞拖尾率高.NIH/3T3细胞受到镍冶炼烟尘的受试物作用后,在染毒2 h,样品1、样品2各剂量组的细胞彗星尾DNA含量、尾长（除12.5 μg/ml剂量组外）、尾动差（除样品1的12.5μg/ml剂量组外）均明显高于阴性对照组,差异有统计学意义（P＜0.05）.在染毒4 h,两样品对细胞DNA的损伤达到高峰,各剂量组的3个指标与对照组的差异有统计学意义（P＜0.05）.染毒时间延长至24 h,上述3个指标改变程度均较染毒4 h减弱,样品1的彗尾长与对照组的差异无统计学意义（P＞0.05）.结论 镍冶炼烟尘可不同程度致NIH/3T3细胞DNA损伤.

Experimental study on the DNA damage of NIH/3T3 cells induced by nickel-refining dusts

OBJECTIVE: To study the effects of nickel-refining dusts on DNA damage in mouse NIH/3T3 cell. METHOD: DNA damage of mouse NIH/3T3 cell induced by two nickel-refining dust samples was determined with single cell gel electrophoresis (SCGE) technique. RESULTS: (1) Under the condition of the same treatment time, the tailed cell (%) of NIH/3T3 cells increased with the increase in doses of nickel-refining dusts (35.5%, 69.7%, 85.2%, 41.3%, 75.7%, 89.2% respectively except for sample 2, 50 microg/ml, 24 h group), and DNA strand breaks reached the peak value at 4 h of exposure; (2) When we treated the NIH/3T3 cells with the same dose of nickel-refining dusts, the tail rate at 4 h was higher than those at 2 h and 24 h of exposure; (3) Both sample 1 and sample 2 with different doses of nickel-refining dusts could induce higher comet tail, DNA%, tail length (except for 12.5 microg/ml), extent of TM (except for sample 1, 12.5 microg/ml) than in control group (P < 0.05). The DNA damage range was significantly increased in different tested doses of nickel-refining dusts and the damage range reached the peak value when the cells were treated for 4 h. CONCLUSION: Nickel-refining dusts could induce different degree DNA damage in NIH/3T3 cells.