气溶胶自由基毒理学机制的研究

The study on free radical toxicological mechanism of aerosols

应用两级核孔滤膜的空气采样器采集了上海市区及郊区农村两点的粗颗粒 (>2 5 μm)及细颗粒 (PM2 5)气溶胶 .用质子激发X荧光 (PIXE)分析了其元素含量及其水溶后样品的元素含量 .用ESR观察了颗粒物中的自由基 ;应用丙二醛 (MDA)和四唑盐 (MTT)方法比较了辐照前后粗颗粒的细胞毒性 .结果显示市区气溶胶粒子中的Fe ,Cr和Mn化合物比郊区粒子中的易溶于水 ,郊区细粒子中的Fe化合物比粗粒子中的易溶于水 .ESR谱显示颗粒物中含有自由基 ,毒理实验显示了辐照后的气溶胶颗粒与未辐照的相比具有更高的细胞毒性 .

The coarse particulate samples (>2 5?μm) and fine particulate samples(PM 2 5 ) were collected from one downtown area of Shanghai and one village place of suburb, by stacked filter air sampler. The element contents in aerosols and in their unsoluble parts were analyzed by PIXE. The free radical signals in particulates wrer detected by ESR. The cytotoxicity of UV radiated particulates was evaluated by MDA and MTT methods. The results show that the compouds of transition metals Cr, Mn, and Fe from downtown dissolve in water than those from suburb both in coarse and fine particulates and Fe compounds in fine particulates (PM 2 5 ) from suburb dissolve in water more easily than those in coarse particulates (>2 5?μm). As soluble Fe compounds can induce OH free radicals by decomposition of H 2O 2, higher contents of soluble Fe and other transition elements in particulates would cause higher cytotoxicity. Furthermore, the free radical signal in particulates was observed by ESR,the cytotoxicity increased as they were irradiated by UV in these experiments. The results suggest that one of the main factors to cytotoxicity is free radicals.