Study type: Medical/biological study (experimental study)

50 Hz magnetic fields activate mussel immunocyte p38 MAP kinase and induce HSP70 and 90. med./bio.

Published in: Comp Biochem Physiol C Toxicol Pharmacol 2004; 137 (1): 75-79

Aim of study (acc. to author)

To investigate the cumulative effect of repeated exposures to extremely low frequency magnetic fields at different intensities on immunocyte functionality.

Background/further details

Mussels (groups of 5 animals) were exposed to 50 Hz magnetic fields with various intensities and different times.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: 30 min - once, twice or thrice with an interval of 3 h

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration 30 min - once, twice or thrice with an interval of 3 h
Exposure setup
Exposure source
Setup pair of Helmholtz coils consisting of two horizontal PVC coated coils (10 cm x 10 cm, 1400 turns of 0.2 mm copper wire), separated by 13 cm
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 300 µT - measured - -
magnetic flux density 400 µT - measured - -
magnetic flux density 600 µT - measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

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.

Study character:

Study funded by

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