This study was performed to investigate the effects of a 60 Hz sinusoidal magnetic field on the cell proliferation of human astrocytoma cells and rat cortical astrocytes in vitro.
Additionally, the role of the temperature, of chemical agonists (carbachol, tetradecanoylphorbol acetate induce DNA synthesis), and the protein kinase C inhibitor (GF 109203X) should be examined.
The experiments were done in triplicate and repeated at least three times.
Exposure duration: 3 - 72 h
|Exposure duration||3 - 72 h|
|Setup||double wrapped square four-coil Merritt system; 0.233 m-square bifiliar coils with 78, 33, 33, 78 turns; cell cultures placed inside the coils; MF perpendicular to plane of cell culture plates|
|Sham exposure||A sham exposure was conducted.|
|magnetic flux density||0.03 mT||effective value||measured||-||-|
|magnetic flux density||0.12 mT||maximum||measured||-||-|
The magnetic field caused a time- and dose-dependent increase in proliferation of human astrocytoma cells, and strongly potentiated the effect of carbachol and tetradecanoylphorbol acetate. However, magnetic field had no effect on DNA synthesis of normal rat cortical astrocytes.
A 0.7 °C temperature increase was observed in the magnetic field (at 1.2 Gauss) exposed and sham exposed medium, however, 3H-thymidine incorporation caused by magnetic field exposure was significantly higher than that induced by sham exposure.
The protein kinase C inhibitor, and arteficial down-regulation of protein kinase C inhibited the effect of magnetic field 3H-thymidine incorporation.
The results indicate that magnetic field can increase the proliferation of human astrocytoma cells and strongly potentiate the proliferation supporting effects of carbachol and tetradecanoylphorbol acetate, probably by the involvement of proteinkinase C.