Effects of 50 Hz ferromagnetic field exposure on apoptosis and proliferation of murine liver cell in vivo

The biological effects of irradiation by magnetic field on the proliferation and apoptosis of the liver cells in mice are studied. BALB/C mice were irradiated by 50 Hz homogeneous ferromagnetic field(0.097 T) and divided into four irradiation groups: 5 min., 30 min., 60 min., and 120 min.. Proliferation and apoptosis of the liver cells were analyzed with the flow cytometry (FCM) and DNA agarose gel electrophoresis. The FCM test results showed that different irradiation time of magnetic field could induce apoptosis of murine liver cells. The percentage of apoptosis in irradiation groups are 9.55%/spl plusmn/0.82%, 12.07%/spl plusmn/2.96%, 13.66%/spl plusmn/1.90% and 16.22%/spl plusmn/2.64% respectively and significantly higher than that in control group. In the interval of 5 min-120 min, the percentage of apoptosis of liver cells increased as the irradiation time prolonged (r=0.78, P<0.05), but FCM results showed that 50 Hz homogeneous ferromagnetic field have no effects on proliferation of murine liver cells. We concluded that irradiation of 50 Hz homogeneous ferromagnetic field could induce and promote apoptosis of murine liver cells in time-effects manner.