葡萄糖介质中铬(V)化合物诱导DNA损伤的机理探讨  

Studies on the mechanism of Cr-induced DNA damage in glouse

作　　者：史黎薇[1] 井海宁[1] 任改英[1] Aviva Levina Peter Lay 

机构地区：[1]中国疾病预防控制中心环境与健康相关产品安全所,北京100021 [2]澳大利亚悉尼大学化学院

出　　处：《卫生研究》2006年第3期348-351,共4页Journal of Hygiene Research

基　　金：澳大利亚科技部基金

摘　　要：目的初步探索铬[Cr(V)]中间化合物在葡萄糖介质中对DNA损伤的反应机理。方法共研究了在4种糖类及3种不同pH值条件下DNA损伤的情况。DNA的损伤通过凝胶电泳测定;反应体系中各物种的寿命及新物种的测定用顺次共振波谱仪检测。结果Cr(V)在葡萄糖介质中具有毒性并可能导致癌症,但不同糖类对DNA的损伤不同,同时随着pH值的增高,DNA的损伤相对较小,这是由于反应体系的酸性增加,Cr(V)化合物发生歧化反应的速度加快以及还原剂氢原子浓度的增加所造成的,同时Cr(V)化合物与葡萄糖产生配位体交换使反应体系产生新的物种,而新物种对DNA也产生损伤。结论根据实验结果初步推断葡萄糖介质中铬(V)化合物诱导DNA损伤的机理。Objective To investigate the mechanism of Cr-induced DNA damage in glouse. Methods The studies were conducted at three pH values（pH6.5, 7.5, 8.5） with a range of sugars, including D-glucose, a-methyl-D-glucose, 2-deoxy-D-glucose, and D-glucose-C-d7. DNA damage was analyzed by gel electrophoresis, and the new species and their lifetime were detected by EPR. Results The results of these experiments have reinforced the postulate that Cr （V） complexes are likely to be involved in the genotoxic damage that eventually results in Cr-induced cancers. With an increase in the pH values, the amount of Form Ⅱ DNA decreased due to the increasing rate of Cr（V） dispreportionation and H concentration. On the other hand, the presence of sugars in the reaction system generated Cr-mixed-ligand complexes, which could also cause DNA cleavage. Conclusion Proposed mechanism of DNA cleavage are presented indueed by Cr （ V ）- mixed-ligand.

关 键 词：铬(Cr(V))中间化合物 DNA损伤 凝胶电泳 顺磁共振波谱仪 

分 类 号：R730.2[医药卫生—肿瘤] O614.611[医药卫生—临床医学]