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EMF Study
(Database last updated on Mar 27, 2024)

ID Number 251
Study Type In Vitro
Model Studies of RF fields (CW and AM) on ODC (ornithine decarboxylase) activity.
Details

L929 fibroblasts, rat C6 glioblastoma, and SH-SY5Y human neuroblastoma cells exposed to 900 MHz (CW & GSM) RF for 2, 8, and 24 hours at 0.2 and 0.4 W/kg and analyzed for ODC activity. In a preliminary report given at BEMS (2001) the authors did not find ODC activity changes at higher (2.4 and 4 W/kg) SAR levels to support the initial findings of Litovitz et al (Bioelectromagnetics 1997, 18:132-141), although controlling temperature was an issue. In a subsequent report at EBEA 2001 in Helsinki using lower exposures (0.3 and 0.5 W/kg), ODC values were actually lower than control values by 40%. This lowering of ODC activity is opposite of the reports of higher ODC activity reported by Litovitz et al. In a published study in 2006, the authors report GSM 900 MHz exposure at 0.2 and 0.4 W/kg did not increase ODC activity in the cells, although temperature increases and time of growth could influence ODC activity results. In a 2007 report, the authors exposed as above, but at higher SAR (1.5, 2.5, and 6 W/kg) (CW, GSM) to L929 cells (replication of Litovitz et al) as well as C6 and SH-SY5Y cells and primary rat astrocytes. In rat primary astrocytes, the authors report significantly decreased ODC levels after 1 and 8 hours with CW and GSM, and after 24 hours following GSM exposure. No effects were reported in cell lines. The authors note the decrease with RF exposure in primary cells is opposite that reported previously. To determine whether the physiological state of the cells may play a role in the different response of cells to RF exposure, the group again exposed L929 cells to 872 Mhz (CW, GSM) at 5 W/kg for 1 or 24 hrs (temperature maintained at 37 +/- 0.3 degrees C) using their enclosed resonator exposure system. Cells were either non-treated, treated with a change of media, or treated with serum deprivation. Change of media increased ODC activity and proliferation, serum deprivation decreased ODC activity and increased caspase-3 activity in sham and RF exposed (1 and 24 hr) cells. RF exposure did not consistently change ODC activity, proliferation, or caspase-3 activity, although there was a non-significant increased trend for ODC activity under all RF exposure conditions. The authors conclude altered physiologic state does not influence the response to RF, whether GSM or CW modulation.

Findings No Effects
Status Completed With Publication
Principal Investigator University of Kuopio, Finland - juutilainen@uku.fi
Funding Agency Nat'l Res Prog, Finland, MMF, GSM Association, TEKES
Country FINLAND
References
  • Hoyto, A et al. Int J Rad Biol, (2008) 84:727-733
  • Hoyto, A et al. Int J Radiat Biol, (2007) 83:367-374
  • Hoyto, A et al. Radiat Environ Biophys, (2006) 45:231-235
  • Hoyto, A et al. Bioelectromagnetics., (2007) 28:501-508
  • Comments

    Part of Perform B studies to replicate reports of changes in ODC activity following non-thermal microwave exposure. The authors could not replicate the findings of Litovitz, but interpret their results as indicating that SAR levels of below 1 W/kg may effect ODC expression levels in some different way. However, it is just as likely that the authors are observing variability in the assay already observed in other laboratories measuring the same endpoint.

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