title: Evaluation of cell viability, DNA single-strand breaks, and nitric oxide production in LPS-stimulated macrophage RAW264 exposed to a 50-Hz magnetic field.
abstract: Synergistic effects between cellular oxidative stress and magnetic fields may explain the adverse biological effects of 50/60 Hz magnetic fields. To determine whether this hypothesis holds in macrophage RAW264 cells, we measured DNA single-strand breaks (SSB), cell viability, and nitric oxide (NO) production in cells with or without exposure to 0.5-mT, 50-Hz magnetic fields for 24 h and with or without simultaneous stimulation via the bacterial endotoxin, lipopolysaccharide (LPS).
  
  
  
  Macrophages stimulated with 10 ng/ml LPS for 1 h were exposed to or not exposed to a magnetic field and were then subjected to (1) the alkaline comet assay to measure SSBs, (2) trypan-blue exclusion assay for cell viability, and (3) measurements of NO for evaluation of oxidative stress.
  
  
  
  The 50-Hz magnetic field enhanced DNA SSB and decreased cell viability only in the LPS-stimulated macrophages in which NO production was greatly enhanced. The magnetic field alone did not alter NO production.
  
  
  
  Co-stimulation of the cell with LPS and a 50-Hz magnetic field promoted SSB and lowered cell viability, but these were not mediated by LPS-induced NO production.
authors.affiliation: a Department of Physics , Tohoku University , Aoba-ku Aramaki , Sendai , Miyagi , Japan.
authors.forename: Maresuke
authors.initials: M
authors.lastname: Nakayama
authors.affiliation: a Department of Physics , Tohoku University , Aoba-ku Aramaki , Sendai , Miyagi , Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Nakamura
authors.affiliation: a Department of Physics , Tohoku University , Aoba-ku Aramaki , Sendai , Miyagi , Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Hondou
authors.affiliation: a Department of Physics , Tohoku University , Aoba-ku Aramaki , Sendai , Miyagi , Japan.
authors.forename: Hidetake
authors.initials: H
authors.lastname: Miyata
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects* / Q000528:radiation effects*; D004249:DNA Damage / Q000502:physiology*; D004307:Dose-Response Relationship, Radiation; D004560:Electricity; D004574:Electromagnetic Fields; D008070:Lipopolysaccharides / Q000008:administration & dosage; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D000067996:RAW 264.7 Cells; D011829:Radiation Dosage
chemical_list: D008070:Lipopolysaccharides; D009569:Nitric Oxide
keywords: Low frequency magnetic field (LFMF); oxidative stress; single-strand breaks/double-strand breaks (SSB/DSB)