硒对氟致小鼠成釉细胞DNA损伤的作用研究

Effects of Selenium on DNA Damage Induced by Fluoride in Mouse Ameloblasts

目的:探讨硒对氟致小鼠成釉细胞DNA损伤的拮抗作用。方法:小鼠成釉细胞未经氟化钠处理为对照组;以氟化钠浓度分别为0.25,0.50,1.00,2.00,4.00mmol/L处理作为单独染氟组;以2.50,5.00,10.00μmol/L Na2SeO3为单独染硒组;以2.50,5.00,10.00μmol/L Na2SeO3+0.25,0.50,1.00,2.00,4.00mmol/L氟化钠为联合作用组。细胞作用24h后,采用单细胞凝胶电泳技术(SCGE)检测DNA单链断裂情况。结果:与对照组相比,单独染硒组小鼠成釉细胞的尾长、Olive尾矩、尾DNA%、尾长/头长值显著性升高(P<0.05),而单独染硒组以上指标均明显下降(P<0.05)。2.50,5.00,10.00μmol/L Na2SeO3+氟化钠联合作用小鼠成釉细胞的尾长、Olive尾矩、尾DNA%、尾长/头长值明显低于对照组和相同剂量单独染氟组(P<0.05),且高于相应剂量的单独染硒组(P<0.05)。与2.50μmol/L Na2SeO3+氟化钠联合染毒组比较,5.00,10.00μmol/L Na2SeO3+各剂量氟化钠联合作用组Olive尾矩均升高(P<0.05)。结论:过量摄入氟化物可导致小鼠成釉细胞DNA损伤,而适量的硒对氟致DNA损伤有一定的拮抗作用,且实验浓度为2.50μmol/L时其拮抗效果较好。

Objective. To investigate the antagonistic effects of selenium on DNA damage caused by flu- oride in mouse ameloblasts. Methods. The mouse ameloblasts were treated with different concen- trations of sodium fluoride （0.25, 0.50, 1.00, 2.00 and 4.00 mmol/L respectively）, or/and dif- ferent concentrations of sodium selenite （2. 50, 5.00, and 10.00 μmol/L respectively） for 24hours. Then the single cell gel electrophoresis assay was used to measure the DNA damage in mouse ameloblasts. Results： As compared with that respectively in the control group, the tail length, olive tail moment, DNA% and tail/head length ratio in mouse ameloblasts of sodium flu- oride groups were higher, while all these DNA damage indexes induced by sodium selenite were lower （all P〈0.05）. When treated with both selenite and fluoride, these indices were lower than those of the control group, and the values were between those of corresponding doses of sodium fluoride groups and sodium selenite groups （P〈0.05）. Compared with that of 2.50 μmol/L sele- nium＋sodium fluoride group, olive tail moment of 5.00 and 10.00 tlmol/L sodium selenite ＋ so- dium fluoride groups were increased significantly （both P〈0.05）. Conclusion： Excessive fluoride could induce DNA damage in mouse ameloblasts, hut selenium under certain dose could antago- nize the DNA damage induced by fluoride, and selenium at the dose of 2.5 μmol/L sodium sele- nite has optimal inhibitive effect.