有持, 秀喜 Department of Bacteriology, The University of Tokushima School of Medicine 徳島大学 教育研究者総覧 KAKEN研究者をさがす
キノウチ, タケミ Department of Bacteriology, The University of Tokushima School of Medicine
片岡, 佳子 Department of Bacteriology, The University of Tokushima School of Medicine 徳島大学 教育研究者総覧 KAKEN研究者をさがす
桑原, 知巳 Department of Bacteriology, The University of Tokushima School of Medicine
1-Nitropyrene (1-NP) is a mutagenic nitro compound in the environment. We studied correlations between the mutagenicity of 1-NP for three strains of Salmonella typhimurium, the activity of bacterial nitroreductases and the amount of 1-NP-derived DNA adducts. Bacterial strains used in this study were S. typhimurium strains TA98, nitroreductase-less mutant TA98NR and YG1021 carrying a nitroreductase-producing plasmid. The mutagenicity of 1-NP was measured using the Ames assay, and the nitroreductase activities of these strains were assayed by quantification of 1-aminopyrene produced from 1-NP. The DNA adducts were measured by the 32P-postlabeling method. Among the three bacterial strains, strain YG1021 was the highest in mutagenicity of 1-NP, the nitroreductase activity and the DNA adduct level. However, S. typhimurium strain TA98NR had the lowest values of these three parameters. Nitroreductase activity, DNA adduct level and mutagenicity were strongly correlated with each other. These results indicate that bacterial nitroreductase plays an important role in forming the DNA adducts, and that the higher the adduct level the higher the level of mutagenicity.
The journal of medical investigation : JMI
jmi_44_3-4_193.pdf 179 KB