Study type: Medical/biological study (experimental study)

50-Hz magnetic field exposure influences DNA repair and mitochondrial DNA synthesis of distinct cell types in brain and kidney of adult mice med./bio.

By: Schmitz C, Keller E, Freuding T, Silny J, Korr H
Published in: Acta Neuropathol 2004; 107 (3): 257-264
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Aim of study (acc. to author)

To investigate the extent of nuclear DNA repair and the relative amount of nuclear DNA single-strand breaks for different cell types in brain and kidney of adult mice after a 50 Hz magnetic field exposure. The question should be answered whether or not DNA damage occurs.

Background/further details

Five minutes after ending exposure, the animals received [³H]thymidine (for autoradiographs) and were killed 2 h later. Autoradiographs were prepared from paraffin sections of brains and kidneys.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 8 weeks

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 8 weeks
Exposure setup
Exposure source
Setup Four cages containing 5 mice each were placed within the inner space of the coils.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.8 mT mean 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)

A significant increase in both unscheduled DNA synthesis and in situ nick translation was only found for epithelial cells of the choroid plexus. Thus, these two independent methods indicate that nuclear DNA damage is produced by long-lasting and strong magnetic field irradiation. The fact that only plexus epithelial cells were affected might point to possible effects of magnetic fields on iron transport across the blood-cerebrospinal fluid (Liquor cerebrospinalis) barrier, but the mechanisms are currently not understood.
Mitochondrial DNA synthesis was exclusively increased in renal epithelial cells of distal convoluted tubules (Tubuli renalis) and collecting ducts, i.e., cells with a very high content of mitochondria, possibly indicating increased metabolic activity of these cells.
In summary, the pilot study has shown that a long-lasting and strong 50 Hz magnetic field exposure with a flux density above 1 mT appears to be able to produce nuclear DNA damage within at least one distinct cell population in the brain.

Study character:

Study funded by

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