Exposure duration: continuous for up to 24 h (30 min, 2 h, 6 h, 12 h, 18 h, 24 h)
|Setup||pair of Helmholtz coils with a radius of 13 cm ± 0,5 cm and 800 turns of wire, placed vertically at a distance of 13.5 cm ± 0.5 cm; stack of 5 culture plates exposed simultaneously; field uniformity better than 1% in the exposure area in the center of the coil system; exposure system placed in an incubator; two identical exposure systems, one for sham exposure and one for real exposure, used in a random fashion|
|Sham exposure||A sham exposure was conducted.|
|magnetic flux density||1 mT||-||-||-||-|
Exposure to extremely low frequency magnetic fields resulted in a transient, but significant increase of myoblast migration at 6 h of exposure. This effect was associated with a marked increase of µ- and m-calpain enzyme activity (at 2 h and 6 h of exposure, respectively) followed by the concomitant variation in their subcellular localization. No significant changes in intracellular distribution and protein levels of calpastatin were found. Finally, a significant decrease of MARCKS protein expression (at 2 h and 6 h of exposure) and modifications of actin dynamics were observed.
The data showed an involvement of calpains in extremely low frequency magnetic field-mediated myoblast migration.