Study type: Medical/biological study (experimental study)

Gender and Age Differences in the Suppressive Effect of a 50 Hz Electric Field on the Immobilization-Induced Increase of Plasma Glucocorticoid in Mice. med./bio.

Published in: Bioelectromagnetics 2020; 41 (2): 156-163

Aim of study (acc. to author)

The suppressive effect of exposure to a 50 Hz electric field on immobilization-induced increase in glucocorticoid level in mice of different age and sex should be invesigated.

Background/further details

Glucocorticoid levels were measured as an indicator for stress. There were 4 different treatments: 1) immobilization and electric field exposure, 2) electric field exposure only, 3) immobilization only, 4) control group. Respectively, a) 6 female mice, b) 6 female mice with ovariectomy, c) 6 young (10 weeks) male mice, d) 6 young (15 weeks) male mice, e) 6 adult (25 weeks) male mice and f) 6 older (55 weeks) male mice were subjected to these treatments and thus a total of 24 different groups were formed (1a-4f). Immobilization stress was applied during the second half (30 min) of the 60‐min exposure period.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: 60 minutes

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration 60 minutes
Exposure setup
Exposure source
Chamber cylindrical plastic cage (diameter: 200 mm; height: 100 mm) with slits (length: 100 mm; width: 5 mm) all around at intervals of 5 mm; the temperature inside the cage was 25 ± 3 °C during the exposure or sham exposure; the humidity was maintained between 45% and 55%; stress was applied by immobilizing each mouse separately within a 50‐ml centrifuge (polypropylene) tube or in immobilization devices; immobilization devices were used in different sizes for different ages of mice
Setup a parallel plate electrode system comprising two stainless steel electrodes (1,000 × 600 mm) that were placed over and under the cylindrical exposure cage; to generate the electric field of 10 kV/m in the cage, 1 kV was applied to the
upper electrode, whereas the counterpart electrode was grounded
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 10 kV/m - measured - ± 4% outside the exposure cage and ± 0.1% inside
magnetic flux density 12 nT - measured - ± 4 nT

Reference articles

  • Hori T et al. (2018): Characterization of the suppressive effects of extremely-low-frequency electric fields on a stress-induced increase in the plasma glucocorticoid level in mice.
  • Hori T et al. (2017): Configuration-dependent variability of the effect of an electric field on the plasma glucocorticoid level in immobilized mice.
  • Harakawa S et al. (2017): Time-dependent changes in the suppressive effect of electric field exposure on immobilization-induced plasma glucocorticoid increase in mice.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Plasma glucocorticoid levels were significantly decreased in all immobilization and electric field exposure groups (groups 1a-1f) compared to immobilization alone (groups 3a-f).
Electric field exposure had no significant effects on the other blood parameters.
The authors conclude that exposure to a 50 Hz electric field might decrease immobilization-induced stress in mice regardless of age and sex.

Study character:

Study funded by

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