[Exposure to power-frequency magnetic fields can induce activation of P38 mitogen-activated protein kinase].
OBJECTIVE
To study the effects of 50 Hz power-frequency magnetic fields on signal transduction pathway of P38 mitogen-activated protein kinase (P38 MAPK), and explore the cellular signal transduction mechanism of the biological effects induced by power-frequency magnetic fields.


METHODS
Chinese hamster lung (CHL) cell line was exposed to power-frequency magnetic fields with two intensities(0.1 and 0.4 mT) for different exposure durations. The cytoplasmic protein was extracted. The phosphorylated(activated) and non-phosphorylated P38 MAPK and MKK3/MKK6 were measured by Western blotting analysis with their specific corresponding antibodies.


RESULTS
Power-frequency magnetic fields at 0.4 mT for 10 min could transitorily induce the activation of P38 MAPK and after 15 min the phosphorylation of P38 MAPK restored to control level, while 0.1 mT power-frequency magnetic fields could not induce the activation of P38 MAPK within 24 h. However, both 0.1 mT and 0.4 mT power-frequency magnetic fields could not phosphorylate(activate) the MKK3/MKK6, which is a general upstream kinase of P38 MAPK.


CONCLUSIONS
Power-frequency magnetic fields could transitorily activate the P38 MAPK, but not MKK3/MKK6. The activation mechanism of P38 MAPK needs to be further identified.
Sun
Wenjun
W
Microwave Lab., Zhejiang University School of Medicine, Hangzhou 310031, China.
Yu
Yingnian
Y
Chiang
Huai
H
Fu
Yiti
Y
Lu
Deqiang
D
D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004789:Enzyme Activation / Q000528:radiation effects; D008168:Lung / Q000201:enzymology / Q000528:radiation effects; D048371:MAP Kinase Kinase 3 / Q000378:metabolism; D048669:MAP Kinase Kinase 6 / Q000378:metabolism; D008280:Magnetics; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism* / Q000528:radiation effects
D048051:p38 Mitogen-Activated Protein Kinases; D048371:MAP Kinase Kinase 3; D048669:MAP Kinase Kinase 6