铬盐与香烟烟雾溶液对A549细胞毒性和DNA断裂的影响

Combinative effect of hexavalent chromium and cigarette smoke solution on cytotoxicity and DNA strand breakage in A549 cells

目的 研究重铬酸钾和香烟烟雾溶液 (CSS)对A5 49细胞的细胞毒性和DNA损伤的联合作用。方法 应用四甲基偶氮唑盐法和单细胞凝胶电泳法检测了重铬酸钾和CSS联合处理对A5 49细胞的细胞毒性以及DNA链的断裂损伤。结果 低浓度重铬酸钾 (0 2～ 0 6μmol/L)与高浓度CSS(10支 /L)联合作用促进了细胞的增殖 ,高浓度重铬酸钾(5 4～ 16 2 μmol/L)与高浓度CSS联合作用表现为明显的细胞毒性。重铬酸钾 (0 2、0 6和 1 8μmol/L)或CSS(0 1、0 2、0 5支 /L)单独处理均可诱导DNA断裂 ,存在一定的剂量 -反应关系。在重铬酸钾的 0 6μmol/L时 ,随CSS(0 1、0 2、0 5支 /L)浓度的升高 ,A5 49细胞DNA链断裂程度逐渐增加。结论 重铬酸钾和CSS对A5 49细胞均有细胞毒性和DNA损伤作用。重铬酸钾和CSS联合处理诱导A5 49细胞DNA链断裂 ,并显著高于两者单独处理引起的DNA链断裂作用。

Objective To study the combinative effect o f hexavalent chromium[Cr(Ⅵ)] and cigarette smoke solution(CSS) on cytotoxicity an d DNA strand breakage of A549 cells. Methods Cytotoxicity and D NA strand breakage of A549 cells were determined by MTT assay and single cell ge l assay(SCGE). Results It was shown that low doses of Cr(Ⅵ) (0 .2-0.6 μmol/L) in combination with high dose of CSS (10 cigarette/L), promote d A549 cells proliferation, while high dose of Cr(Ⅵ) (5.4-16.2 μmol/L) in co mbination with high dose of CSS (10 cigarette/L) had obvious cytotoxicity in A5 49 cells. Cr(Ⅵ) or CSS alone induced DNA damage in a dose dependent manner. Com bination of Cr(Ⅵ) and CSS also induced DNA strand breakage in A549 cells. The h igher dose of CSS presented, the more degrees of DNA damage were produced at the same dose of Cr(Ⅵ). Conclusion It was suggested that Cr(Ⅵ) o r CSS alone could produce cytotoxicity in A549 cells, and that Cr(Ⅵ) in combina tion with CSS could produce combinative effect on DNA damage and cytotoxicity in A549 cells.