Hirose, H. Sasaki, A. Ishii, N. Sekijima, M. Iyama, T. Nojima, T. and Ugawa, Y. 1950 MHz IMT-2000 field does not activate microglial cells in vitro. Bioelectromagnetics. 2009 Jul 31.
Potential effects of radiofrequency fields (RF) exposure on brain functions are the subject of considerable research. Microglial cells are immune cells of the central nervous system (CNS). They are activated in response to CNS injury displaying morphological changes, producing antigens and releasing cytokines.
The aim of the study was to investigate whether exposure to RF induces activation of microglial cells at exposure levels up to 2 W/kg, the limit of the average whole body SAR recommended by ICNIRP.
Primary-microglial cell cultures from newborn rats were exposed for 2 hours to 1.95 GHz Wideband Code Division Multiple Access (W-CDMA) RF field at SARs of 0.2, 0.8 and 2 W/kg, or sham exposed. Activation of microglial cells was assessed by evaluating changes in expression of MHC class II antigens (by immunocytochemistry) and production of inflammatory cytokines - tumor necrosis factor a (TNF-a), interleukin-1b (IL-1b) and interleukin-6 (IL-6) - by cytokine production assay.
There were no statistically significant differences in the percentage of MHC class II positive cells between the RF exposed groups at any SAR level and the sham-exposed controls. Exposure to RF at any level did not produce significant changes in TNF-a, IL-1b or IL-6.
Interpretation and Conclusion
The results of this study are in line with the findings of another study, in which, the authors, using TNF-a and IL-6 release and ED1 expression as microglial activity markers, did not detect any effect of 900 MHz radiation on glial cells. Taken together, these findings provide no evidence that exposure to RF radiation up to 2 W/kg activates microglial cells in vitro.