三种汽油增氧剂对小鼠成纤维细胞DNA损伤的研究

目的 比较3种汽油增氧剂对小鼠成纤维细胞DNA的损伤作用。方法 采用单细胞凝胶电泳试验（彗星试验）对3种汽油增氧剂甲基叔丁基醚（MTBE）、无水乙醇（EA）和碳酸二甲酯（DMC）所致的L－929小鼠成纤维细胞的DNA损伤进行了研究。结果 在一定浓度范围内（37.500-150.000mg/ml)，MTBE可直接引起L－929小鼠成纤维细胞的DNA损伤，出现拖尾的彗星细胞。其拖尾细胞百分率和DNA迁移长度均随受试物浓度的增加而增加，且有明显的剂量－效应关系，即MTBE浓度从9.375mg/ml增加到150.000mg/ml时，彗星率从接受阴性对照组的4％增加到接近阳性对照组的85％,彗尾长度也发生了相应的改变。而EA和DMC无此关系。结论 在本试验条件下（浓度为150.00mg/ml)，MTBE对DNA具有明显的损伤作用；未发现EA和DMC对DNA的损伤作用。

Study on three kinds of gasoline oxygenates-induced DNA damage in mice fibroblasts

OBJECTIVE: To study DNA damage of three kinds of gasoline oxygenates. METHOD: Single cell gel electrophoresis assay(Comet assay) was used to detect the damage effects of three gasoline oxygenates[methyl tertiary butyl ether(MTBE), ethanol anhydrous(EA) and dimethyl carbonate(DMC)] on DNA in L-929 mice fibroblasts. RESULTS: In certain concentation(37.500-150.000 mg/ml), MTBE could directly cause DNA damage of L-929 mice fibroblasts. There was obvious dose-effect relationship, i.e. when the concentration of MTBE was increased from 9.375 to 150.000 mg/ml, the comet rate also increased from 4% to 85%, and the length of comet tail changed correspondingly. The results of EA and DMC were negative. CONCLUSION: Under the condition of this experiment(150.000 mg/ml), MTBE could directly cause DNA damage while the effect of EA and DMC on DNA damage was not found.