title: ELF electromagnetic fields increase hydrogen peroxide (H2O2)-induced mutations in pTN89 plasmids.
abstract: We have examined the mutational effects of hydrogen peroxide (H(2)O(2)) in the presence and absence of an extremely low-frequency magnetic field (ELFMF), using pTN89 plasmids. Mutations were detected in the supF gene carried by these plasmids in Escherichia coli. The plasmids were either treated with H(2)O(2) (1microM) alone at 37 degrees C for 4h, or were exposed to an ELFMF (60Hz, 5millitesla (mT)) simultaneously with H(2)O(2) treatment. The mutation frequency was 2.28 x 10(-4) for H(2)O(2) treatment alone, and 5.81 x 10(-4) for ELFMF exposure with H(2)O(2) treatment. We did not observe any mutations using treatment with ELFMF exposure alone. This indicates that the ELFMF may potentiate H(2)O(2)-induced mutation. Sequence analysis of the supF mutant plasmids revealed that base substitutions, G: C-->A :T transitions and G:C-->T:A transversions were dominant in both treatment groups, and there was no difference in the mutation spectrum or the hotspots between the groups. Therefore, ELFMFs may interact and potentiate the damage induced by H(2)O(2), resulting in an increase in the number of mutations.
authors.affiliation: Department of Radiological Technology, Faculty of Medicine, School of Health Sciences, Hirosaki University, 66-1 Hon-cho, Hirosaki 036-8564, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Koyama
authors.forename: Takehisa
authors.initials: T
authors.lastname: Nakahara
authors.forename: Hideki
authors.initials: H
authors.lastname: Hirose
authors.forename: Gui-Rong
authors.initials: GR
authors.lastname: Ding
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Takashima
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Isozumi
authors.forename: Junji
authors.initials: J
authors.lastname: Miyakoshi
mesh_terms: D001483:Base Sequence; D004247:DNA; D004574:Electromagnetic Fields; D016153:Genes, Suppressor; D006861:Hydrogen Peroxide / Q000633:toxicity*; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids / Q000187:drug effects* / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics; D014162:Transfection
chemical_list: C096275:supF tRNA; D004247:DNA; D012343:RNA, Transfer; D006861:Hydrogen Peroxide