Study type: Medical/biological study (experimental study)

The effects of extremely low-frequency electromagnetic fields on c-Maf, STAT6, and RORα expressions in spleen and thymus of rat. med./bio.

Published in: Electromagn Biol Med 2019: 1-7 [in press]

Aim of study (acc. to author)

The effects of exposure of rats to 50 Hz magnetic fields on gene expressions of transcription factors related to T cell differentiation in thymus and spleen should be investigated.

Background/further details

Rats were divided randomly into the following groups (n=16 each): 1) exposure to a 1 µT magnetic field, 2) exposure to a 100 µT magnetic field, 3) exposure to a 500 µT magnetic field, 4) exposure to a 2000 µT magnetic field, 5) sham exposure. All rats received human serum albumin intraperitoneally (100 μg/rat) on days 31, 44, and 58 of exposure to stimulate the immune system and induce T cell differentiation. The animals were observed daily for overall health and well-being and were killed after exposure to remove thymus and spleen.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: 2 hours/day for 2 months
Exposure 2: 50 Hz
Exposure duration: 2 hours/day for 2 months
Exposure 3: 50 Hz
Exposure duration: 2 hours/day for 2 months
Exposure 4: 50 Hz
Exposure duration: 2 hours/day for 2 months

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration 2 hours/day for 2 months
Exposure setup
Exposure source
Chamber standard plastic laboratory cages (4 rats/cage) with constant environmental conditions (temperature of 22 ± 2°C, relative humidity of 55–65% and 12 h light/dark cycle)
Setup solenoids were made of polyvinyl chloride tubes with 40 cm internal diameter, 2 m length and different numbers of turns of wires; combination of different turns of wires with different voltages was applied in each solenoid to produce different magnetic flux densities; the temporal field homogeneity was 98.5%; spatial homogeneity was not assessable due to the excessive length of the solenoid (2 m), but should be acceptable in theory; time of exposure for all groups was similar (8–10 a.m.)
Sham exposure A sham exposure was conducted.
Additional info sham exposure group was placed in the solenoid when it was not connected to electricity
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 µT - measured - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration 2 hours/day for 2 months
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT - measured - -

Exposure 3

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration 2 hours/day for 2 months
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 500 µT - measured - -

Exposure 4

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration 2 hours/day for 2 months
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2,000 µT - measured - -

Reference articles

  • Salehi I et al. (2013): Exposure of rats to extremely low-frequency electromagnetic fields (ELF-EMF) alters cytokines production.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

In the spleen, the gene expression levels of RORα and c-Maf were significantly down-regulated in groups 1 and 2 (1 µT and 100 μT) compared to the sham exposure group, while the gene expression of STAT6 was only significantly down-regulated in group 2. No significant changes were detected in the thymus.
The authors conclude that exposure of rats to weak 50 Hz magnetic fields might down-regulate the gene expression of transcription factors c-Maf, STAT6 and RORα in the spleen.

Study character:

Study funded by

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