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; 38 (2): 177-183

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 Method
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 Method
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 Method
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 Method
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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