To study the effects of extremely low frequency electromagnetic fields on the number of apoptotic cells of K562 cell line, subjected or not to oxidative stress (induced by hydrogen peroxide at the onset of exposure) and to correlate the data with heat-shock protein and reactive oxygen species levels.
Exposure duration: continuous for 3 hr
|Exposure duration||continuous for 3 hr|
|magnetic flux density||1 mT||-||measured||-||-|
When K562 cells were treated with hydrogen peroxide alone the ratio of apoptotic cells increased by about 70% and cell viability decreased. A further increase in the number of apoptotic cells was observed upon extremely low frequency electromagnetic field exposure to hydrogen peroxide treated cells indicating that electromagnetic field acted as a co-stressor. Correspondingly, extremely low frequency electromagnetic field irradiation caused a slight decrease in cell viability of cells treated with hydrogen peroxide.
A 30% increase in reactive oxygen species levels in electromagnetic field exposed cells was observed (compared to the controls). This increase was larger than the increase induced by hydrogen peroxide alone. Electromagnetic field exposure caused a slight increase in reactive oxygen species levels of hydrogen peroxide treated cells compared with hydrogen peroxide alone (but this increase was not as high as the increase caused by the electromagnetic field exposure alone). These data indicate that extremely low frequency electromagnetic field exposure did not act synergistically with hydrogen peroxide.
Additionally, a significant increase in hsp70 expression was observed upon extremely low frequency electromagnetic field exposure of hydrogen peroxide treated cells compared with hydrogen peroxide treated cells alone. However, it was not statistically singificant compared with cells exposed to the electromagnetic field alone.