|Exposure duration||30 min - once, twice or thrice with an interval of 3 h|
Animals exposed at 300 µT for three different times did not show differences in the heat shock protein expression in comparison with non-exposed mussels. At 400 µT, exposed animals showed a time-dependent increase in heat shock protein expression. After exposure to 600 µT, the heat shock protein expression was significantly higher than controls but independently from exposure duration. The induction of heat shock proteins is concomitant with the activation of p38 MAP kinase signalling pathway. The p38 MAP kinase phosphorylation was just as well intensity-dependent but independent of the time of exposure.
The findings suggest the possibility to modulate the expression of heat shock proteins by magnetic field exposure. Only the exposure to a magnetic field strength of 400 µT at all three durations sorted a cumulative effect and resulted in a gradual increase of HSP70 and HSP90 expression.