【摘要】 目的　以体外培养的人肺泡上皮细胞 (A549)作为靶细胞 ,探讨煤尘对DNA的损伤作用。方法　将人肺泡上皮细胞 (A549)用 3种煤尘作用 2h或 2 4h,用MTT法测定细胞存活情况及用单细胞凝胶电泳技术测定DNA链断裂情况 ;采用两种细胞共培养的方法 ,用MTT法测定煤尘在巨噬细胞介导作用下对A549细胞存活情况的影响及用单细胞凝胶电泳技术测定DNA链断裂情况。结果　 3种煤尘 (游离SiO2 含量分别为 4 33%、1 79%、0 67% )以 3种剂量 (1 0 0、50 0、1 0 0 0 μg ml)直接作用于A549细胞 2 4h,在 50 0和1 0 0 0 μg ml时均可引起细胞存活率的明显下降 ;直接作用于A549细胞 2h或 2 4h及通过巨噬细胞介导作用下A549细胞 ,均未能引起A549细胞DNA链断裂程度的明显增加。结论　煤尘对A549细胞具有明显的细胞毒性 ,但不具有明显的遗传毒性更多还原

【Abstract】 Objective To study the DNA damage induced by coal dust directly or mediated by alveolar macrophages(AM)in A549 cells.Methods A549 cells were exposed to three kinds of coal dust for 2 or 24 h,or A549 cells and AM were co\|cultured and only AM were exposed to coal dust,then MTT assay was used to detect the cell survival and SCGE assay was used to detect DNA damage in A549 cells.Results All three kinds of coal dust(the concentration of free SiO\-2 were 4\^33%,1\^79% and 0\^67% respectively)could induce A549 cells death after 24 h direct exposure,but induce A549 cells proliferation after 24 h exposure to AM in the co\|culture system.Coal dust could no induce DNA damage of A549 cells in direct exposure or in co\|culture system.Conclusion Coal dust presented obvious cytotoxicity to A549 cells but no obvious genotoxicity to A549 cells when direct exposed or mediated by AM.更多还原