Intracellular generation of reactive oxygen species and dna damage in escherichia coli mutants exposed to electromagnetic field and X-Ray

摘要

In order to examine intracellular generation of reactive oxygen species (ROS) and DNA damage in bacterial cells exposed to extremely low frequency magnetic field (ELFMF) at 400mT and 50Hz and X-ray, 'kat-sod Assay' ad rec-lac Assay' were performed using E. coli mutants which were deficient in ROS scavenging enzymes, such as superoxide dismutase and/or catalase, and DNA repair capacities. Both assays were developed by Nishioka H. And Hayashi S. (1995) and Nunoshia T. and Nishioka H. (1991) and consisted of survival test and β-galactosidase test. X-irradiation induced a clear intracellular generation of ROS and DNA damage, indicating a possibility that intracellular generated ROS may playa partial role in DNA damage by X-ray. On the other hand, no remarkable effects of ELFMF were seen in the cells using y 'kat-sod Assay' And rec-lac Assay', showing that ELFMF did not generate ROS intracellularly and damage DNA.