| Backgrounds Power frequency magnetic fields (PFMF) refer to the extremely low frequency electromagnetic fields (ELF MF) with frequency of50Hz. The bio-effects of PFMF have caused wide public concern over the recent years, which make the genetic effects assessing of PFMF exposure became an important and urgent event in public health. But until now, researches on the genetic effects of PFMF are inconsistent and controversial in this study. We evaluated the DNA damage of three different types of cells exposed to PFMF at different intensities and exposure times, respectively, by using an early and sensitive molecular marker-yH2AX, in the purpose of selecting the sensitive cells of PFMF and investigating their further biological effects.Methods Human amnion epithelial (FL) cells, human umbilical vein endothelial (HUVEC) cells and human skin fibroblast (HSF) cells were exposed to50Hz PFMF at intensity of0.4mT,1mT and2mT for15minutes,1hour and24hours, respectively. Meanwhile, cells for positive control were exposed to0.5or1micromole4-nitroquinoline-l-oxide for1hour. After treatments, cells were subjected to yH2AX foci formation analysis by yH2AX immunofluorescence. The mean number of foci, the percentage of yH2AX foci positive cells and the foci distribution were analyzed in yH2AX foci formation assay. And we also detected the expression of yH2AX protein by using western blot. Each experiment was independently repeated at least three times for blind. Results yH2AX immunofluorescence analyses showed no significant difference in average number of foci per cell, percentage of yH2AX foci positive cells or protein expression of yH2AX between sham-exposure and PFMF-exposure groups (P>0.05). But the foci distribution of cells exposed to PFMF at some individual intensitie or time point showed statistical difference (P<0.05).Conclusions Under current experimental conditions, PFMF did not induced DNA damage in FL cells, HUVEC cells and HSF cells. |
