Study type: Medical/biological study (experimental study)

Short- and long-term exposure to alternating magnetic field (50 Hz, 0.5 mT) affects rat pituitary ACTH cells: stereological study. med./bio.

Published in: Environ Toxicol 2016; 31 (4): 461-468

Aim of study (acc. to author)

The effects of an acute (1+7 days) or chronic (up to 3 months) exposure of rats to a 50 Hz magnetic field on the pituitary and the adrenocorticotropic hormone (ACTH)-producing cells should be investigated.

Background/further details

The adrenocorticotropic hormone is excreted in cases of various forms of stress (possible stressors are work, injuries, diseases, operations, emotions, depressions, physical and psychic stress) and is therefore regarded as a stress hormone.
Rats were divided into 4 groups: 1) exposure to the magnetic field for 1 day (n=6-8), 2) exposure for 7 days (n=6-8), 3) exposure up to 3 months of age (n=6-8) and 4) sham exposure (n=?). In groups 1) and 2), 3-month-old rats were exposed. In group 3), exposure started during mating of the parental generation and rats were exposed from their conception. Sham exposure was conducted separately for each exposure group but as the results were identical, they were considered as only one sham exposure group (remark EMF-Portal: size of group not clear).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 1 day
Exposure 2: 50 Hz
Exposure duration: continuous for 7 days
Exposure 3: 50 Hz
Exposure duration: continuous for up to 3 months of age

General information

geomagnetic field in the experimental area was measured and within the normal range

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 1 day
Exposure setup
Exposure source
Setup an electromagnet with a regular laminated transformer core and pole diameter of 9.5 cm generated a relatively homogenous field; a cage with 4-5 animals, respectively, was placed on each side of the electromagnet at a distance of 20 cm from the center of each cage to the magnetic poles; temperature was maintained at 23 ± 2°C and relative humidity at 60-70%
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.5 mT mean - - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 7 days
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.5 mT mean - - -

Exposure 3

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for up to 3 months of age
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.5 mT mean - - -

Reference articles

  • Raus S et al. (2012): Extremely low frequency magnetic field induced changes in motor behaviour of gerbils submitted to global cerebral ischemia.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Rats exposed to the magnetic field for 1 day (group 1) showed a significantly reduced pituitary volume, total number and volume of adrenocorticotropic hormone-producing cells and their nuclei compared to the sham exposure group, while rats exposed for 7 days (group 2) only showed a significantly reduced volume of ACTH-producing cells.
Rats exposed for up to 3 months of age (group 3) showed a significantly reduced volume of the pituitary and the ACTH-producing cells in comparison to the sham exposure group.
The authors conclude that an acute as well as a chronic exposure of rats to a 50 Hz magnetic field could have an effect on the morphometry of the pituitary and the adrenocorticotropic hormone-producing cells.

Study character:

Study funded by

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