For further information on the setup see also: Tuncel, H., Shimamoto,F., Cagatay, P., Kalkan, M. T. (2002). Variable E-cadherin expression in a MNU-induced colon tumor model in rats which exposed with 50 Hz frequency sinusoidal magnetic field. Tohoku J. Exp. Med. 198:245-249
Cells were treated in the following groups: i) single EMF exposure (exposure 1) ii) repetitive EMF expsoure (exposure 2) iii) exposure 1 + magnesium iv)exposure 2 + magnesium v) exposure 1 + heat shock vi) exposure 2 + heat shock
|Exposure duration||continuous for 1 h|
|Exposure duration||continuous for 1 h/day for 4 days|
The data showed that single exposure to an extremely low frequency electromagnetic field resulted in a decrease in cell differentiation, while extremely low frequency electromagnetic field applied everyday for 1 h caused an increase in cell differentiation (compared with controls). The effect of co-stressors (magnesium and heat-shock) was similar to the results obtained by extremely low frequency electromagnetic field exposure alone.
Extremely low frequency electromagnetic field exposure increased reactive oxygen species levels in K562 cells not treated with hemin. However, electromagnetic field exposure did not change reactive oxygen species levels of hemin treated cells indicating that reactive oxygen species were not the cause for the decrease or increase of cell differentiation.
In conclusion, these findings imply that the time-course of exposure is an important parameter determining the physiological response of cells to extremely low frequency electromagnetic fields.