Effects of 50 Hz Magnetic Fields With Different Intensities Exposure on Delayed Rectifier Potassium Channel of Neurons

There is a growing concern about the relationship between the human health and the biological effects caused by the magnetic fields exposure. The cortical neurons isolated from the mice were exposed to 50 Hz magnetic fields (EMF 1 mT, 5 mT, 10 mT) for 15 min, and then the currents of the delayed rectifier potassium channel were recorded off-line using the whole-cell patch clamp technique to investigate the effects of EMF on channels for the first time. Compared to the control group, there was a significant inhibition on the I-k after exposure to EMF, and with the increase of the voltage depolarization, the inhibition rates of 1 mT and 5 mT almost unchanged and the inhibition rates were (30.0 +/- 4.2)% and (20.0 +/- 2.2)%, respectively. While the inhibition rate of 10 mT became larger and the maximum inhibition rate was 43.4%. Additionally, 1 inT and 5 mT magnetic fields both affected the activation characteristics of delayed rectifier potassium channel, the half activation voltage became larger and the slope factor unchanged, while 10 mT magnetic fields did :not changed anything. This paper indicated that the structure and function of the channel protein on cell membrane may be altered by 50 Hz EMF, and there were different effects on the channel for different strength of magnetic fields, the window effects of strength of magnetic fields were improved in this study.