Laboratory of Genetic Ecotoxicology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic.
Toxicol Lett. 2010 Oct 20;198(3):304-11. doi: 10.1016/j.toxlet.2010.06.016. Epub 2010 Jun 30.
An acellular assay consisting of calf thymus DNA with/without rat liver microsomal S9 fraction was used to study the genotoxicity of complex mixtures of organic air pollutants bound to size segregated aerosols by means of DNA adduct analysis. We compared the genotoxicity of the organic extracts (EOMs) from three size fractions of aerosol ranging from 0.17μm to 10μm that were collected by high volume cascade impactors in four localities of the Czech Republic differing in the extent of the environmental pollution: (1) small village in proximity of a strip mine, (2) highway, (3) city center of Prague and (4) background station. The total DNA adduct levels induced by 100μg/ml of EOMs were analyzed by (32)P-postlabelling analysis with a nuclease P1 method for adduct enrichment. The main finding of the study was most of the observed genotoxicity was connected with a fine particulate matter fraction (<1μm). The concentrations of carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) in EOMs indicate that fine fractions (0.5-1μm) bound the highest amount of c-PAHs in all aerosol sampling sites, which might be related to the higher specific surface of this fraction as compared with a course fraction (1-10μm) and higher mass as compared with a condensational fraction (0.17-0.5μm). As for aerosol mass, both fine and condensational fractions are effective carriers of c-PAHs. Similarly, the DNA adduct levels per m(3) of air were highest for the fine fraction, while the condensational fraction (strip mine site and city center) revealed the highest DNA adduct levels in cases where aerosol mass is taken into consideration. A strong correlation was found between the c-PAHs and DNA adduct levels induced by EOMs in all the localities and for various size fractions (R(2)=0.98, p<0.001). It may be concluded that the analysis of total DNA adducts induced in an acellular assay with/without metabolic activation represents a relatively simple method to assess the genotoxic potential of various complex mixtures.
采用无细胞分析方法，使用小牛胸腺 DNA 与/或大鼠肝微粒体 S9 部分，通过 DNA 加合物分析，研究与大气气溶胶分段粒径结合的有机空气污染物混合物的遗传毒性。我们比较了从捷克共和国四个不同环境污染程度的地点收集的大气气溶胶三个分段粒径（0.17μm 至 10μm）的有机提取物（EOM）的遗传毒性：（1）靠近露天矿的小村庄，（2）高速公路，（3）布拉格市中心和（4）背景站。用核酶 P1 法进行加合物富集，通过（32）P-后标记分析，分析 100μg/ml EOM 诱导的总 DNA 加合物水平。研究的主要发现是，大部分观察到的遗传毒性与细颗粒物（<1μm）有关。EOM 中致癌多环芳烃（c-PAHs）的浓度表明，在所有气溶胶采样点，细颗粒（0.5-1μm）结合了最高量的 c-PAHs，这可能与该部分的比表面积高于粗颗粒（1-10μm）和质量高于冷凝部分（0.17-0.5μm）有关。就气溶胶质量而言，细颗粒和冷凝部分都是 c-PAHs 的有效载体。同样，以每立方米空气计，DNA 加合物水平以细颗粒最高，而以气溶胶质量计，在考虑到气溶胶质量时，冷凝部分（露天矿和市中心）则显示出最高的 DNA 加合物水平。在所有地点和各种粒径中，都发现 EOM 诱导的 c-PAHs 与 DNA 加合物水平之间存在很强的相关性（R（2）=0.98，p<0.001）。可以得出结论，在有无代谢激活的无细胞分析中分析总 DNA 加合物，可以相对简单地评估各种复杂混合物的遗传毒性潜力。
