title: Noise magnetic fields abolish the gap junction intercellular communication suppression induced by 50 hz magnetic fields.
abstract: Previously, we have reported that exposure to 50 Hz coherent sinusoidal magnetic fields (MF) for 24 h inhibits gap junction intercellular communication (GJIC) in mammalian cells at an intensity of 0.4 mT and enhances the inhibition effect of 12-O-tetradecanoylphorbol-13-acetate (TPA) at 0.2 mT. In the present study, we further explored the effects of incoherent noise MF on MF-induced GJIC inhibition. GJIC was determined by fluorescence recovery after photobleaching (FRAP) with a laser-scanning confocal microscope. The rate of fluorescence recovery (R) at 10 min after photobleaching was adopted as the functional index of GJIC. The R-value of NIH3T3 cells exposed to 50 Hz sinusoidal MF at 0.4 mT for 24 h was 30.85 +/- 14.70%, while the cells in sham exposure group had an R-value of 46.36 +/- 20.68%, demonstrating that the GJIC of NIH3T3 cells was significantly inhibited by MF exposure (P < .05). However, there were no significant differences in the R-values of the sham exposure, MF-plus-noise MF exposure (R: 49.58 +/- 19.38%), and noise MF exposure groups (R: 46.74 +/- 21.14%) (P > .05), indicating that the superposition of a noise MF alleviated the suppression of GJIC induced by the 50 Hz MF. In addition, although MF at an intensity of 0.2 mT synergistically enhanced TPA-induced GJIC inhibition (R: 24.90 +/- 13.50% vs. 35.82 +/- 17.18%, P < .05), further imposition of a noise MF abolished the synergistic effect of coherent MF (R: 32.51 +/- 18.37%). Overall, the present data clearly showed that although noise MF itself had no effect on GJIC of NIH3T3 cells, its superposition onto a coherent sinusoidal MF at the same intensity abolished MF-induced GJIC suppression. This is the first report showing that noise MF neutralizes 50 Hz MF-induced biological effect by using a signaling component as the test endpoint.
authors.affiliation: Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Qunli
authors.initials: Q
authors.lastname: Zeng
authors.forename: Xueqin
authors.initials: X
authors.lastname: Ke
authors.forename: Xiangwei
authors.initials: X
authors.lastname: Gao
authors.forename: Yiti
authors.initials: Y
authors.lastname: Fu
authors.forename: Deqiang
authors.initials: D
authors.lastname: Lu
authors.forename: Huai
authors.initials: H
authors.lastname: Chiang
authors.forename: Zhengping
authors.initials: Z
authors.lastname: Xu
mesh_terms: D000818:Animals; D002450:Cell Communication / Q000187:drug effects / Q000528:radiation effects*; D005453:Fluorescence; D017629:Gap Junctions / Q000187:drug effects / Q000528:radiation effects*; D008280:Magnetics; D051379:Mice; D018613:Microscopy, Confocal; D041681:NIH 3T3 Cells; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D013755:Tetradecanoylphorbol Acetate