title: Evaluation of mutagenicity and co-mutagenicity of strong static magnetic fields up to 13 Tesla in Escherichia coli deficient in superoxide dismutase.
abstract: OBJECTIVE
  To evaluate the biological effects of static magnetic fields (SMFs) up to 13 Tesla (T), with respect to superoxide behavior, by determining the effect on mutagenicity in superoxide dismutase (SOD)-deficient Escherichia coli strain QC774, and its parental strain GC4468.
  
  
  METHODS
  Experimental strains were exposed to a 5, 10, or 13T SMF for 24 h at 37°C in Luria-Bertani medium. To evaluate mutagenicity after SMF exposure, the mutation frequency in thymine synthesis genes was determined. The effect of exposure to a 5 or 13T SMF on mutagenicity induced by plumbagin was also investigated.
  
  
  RESULTS
  No statistically significant differences in the mutation frequency in thymine synthesis genes were observed between SMF-exposed cells and unexposed cells at any of the applied magnetic flux densities. Furthermore, exposure to SMFs up to 13T did not affect mutagenicity induced by plumbagin.
  
  
  CONCLUSIONS
  Exposure to SMFs up to 13T caused neither mutagenicity nor co-mutagenicity in the SOD-deficient E. coli strain QC774 or in its parental strain GC4468, suggesting that exposure to strong SMFs does not affect the behavior of superoxides in these microorganisms.
authors.affiliation: Biotechnology Laboratory, Human Science Division, Railway Technical Research Institute, Kokubunji-shi, Tokyo, Japan. syoshie@rtri.or.jp
authors.forename: Sachiko
authors.initials: S
authors.lastname: Yoshie
authors.forename: Masateru
authors.initials: M
authors.lastname: Ikehata
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Hirota
authors.forename: Taro
authors.initials: T
authors.lastname: Takemura
authors.forename: Takashi
authors.initials: T
authors.lastname: Minowa
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Hanagata
authors.forename: Toshio
authors.initials: T
authors.lastname: Hayakawa
mesh_terms: D002470:Cell Survival / Q000528:radiation effects; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics* / Q000528:radiation effects*; D060526:Magnetic Fields; D016296:Mutagenesis / Q000528:radiation effects*; D009285:Naphthoquinones; D013482:Superoxide Dismutase / Q000172:deficiency / Q000235:genetics; D013941:Thymine
chemical_list: D009285:Naphthoquinones; D013482:Superoxide Dismutase; D013941:Thymine; C014758:plumbagin