Study type: Medical/biological study (experimental study)

Extremely low frequency electromagnetic fields activate the ERK cascade, increase hsp70 protein levels and promote regeneration in Planaria. med./bio.

Published in: Int J Radiat Biol 2009; 85 (10): 851-859

Aim of study (acc. to author)

The planaria was used a as a model organism to determine whether an intermittent modulated extremely low frequency electromagnetic field produces elevated levels of the heat shock protein Hsp70 and stimulates intracellular pathways known to be involved in injury and repair.

Background/further details

Planaria were transected equidistant between the tip of the head and the tip of the tail. Individual head and tail portions from the same worm were exposed.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: 1 h twice daily for 15 days

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Waveform
Exposure duration 1 h twice daily for 15 days
Exposure setup
Exposure source
Setup 22 cm x 24 cm Helmholtz coils with a spacing of 10.5 cm, consisting of 164 turns of 19 G Copper wire bundles on a Plexiglas form; samples placed on a Plexiglas stand between the coils; coils enclosed in a 30 cm high, 0.04 inch thick cylindrical mu metal container with a diamter of 15 cm, placed inside an incubator
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 8 µT - measured - -
magnetic flux density 9.5 µT - measured - DC field

Reference articles

  • Goodman R et al. (1998): Magnetic field stress induces expression of hsp70.
  • Jin M et al. (1997): Biological and technical variables in myc expression in HL60 cells exposed to 60 Hz electromagnetic fields.
  • Goodman R et al. (1992): Transcription in Drosophila melanogaster salivary gland cells is altered following exposure to low-frequency electromagnetic fields: analysis of chromosome 3R.
  • Goodman R et al. (1989): Exposure of human cells to low-frequency electromagnetic fields results in quantitative changes in transcripts.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

Extremely low frequency electromagnetic field exposure during the initial three days post-surgery caused a significant increase in regeneration for both heads and tails, but especially tails. The first appearance of eyes occurred at day seven post-transection in exposed tail portions. In the sham exposure control tail samples the initial appearance of eyes occurred 48 h later. Concurrently, exposed heads and tails exhibited an elevation in the level of Hsp70 protein, an activation of an ERK cascade, and an increase in the SRF-SRE binding.
In conclusion, the data showed that exposure to an extremely low frequency electromagnetic field facilitates regeneration in planaria. This effect was accompanied by an increase in the level of the chaperone protein Hsp70 and by the activation of the ERK cascade and downstream transcription factors.

Study character:

Study funded by

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