Study type: Medical/biological study (experimental study)

Exposure to an Extremely-Low-Frequency Magnetic Field Stimulates Adrenal Steroidogenesis via Inhibition of Phosphodiesterase Activity in a Mouse Adrenal Cell Line med./bio.

By: Kitaoka K, Kawata S, Yoshida T, Kadoriku F, Kitamura M
Published in: PLoS One 2016; 11 (4): e0154167-
Download citation in RIS format

Aim of study (acc. to author)

The effects of exposure of mouse and human adrenal cortex-derived cells to a 60 Hz magnetic field on steroid hormone production and the underlying mechanisms of action should be investigated.

Background/further details

Except for one test, all experiments, a magnetic flux density of 1.5 mT was used. Only for the quantification of corticosterone, mouse adrenal cortex-derived cells were exposed to 0.25 mT, 0.5 mT, 1.5 mT and 3 mT.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: for 1 h, 6 h, 24 h or 48 hours
Exposure 2: 60 Hz
Exposure duration: for 24 hours
Exposure 3: 60 Hz
Exposure duration: for 24 hours
Exposure 4: 60 Hz
Exposure duration: for 24 hours

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Exposure duration for 1 h, 6 h, 24 h or 48 hours
Exposure setup
Exposure source
Chamber cell culture dishes in incubator
Setup the exposure apparatus consisted of a cylindrical plastic (polyvinyl chloride) container (37 cm outer diameter, 34.5 cm inner diameter, 33 cm length) placed vertically with a coil inside; the coil consisted of one primary coil and two secondary coils that were placed on the upper and lower ends of the primary coil; coils were made of enameled wires (2.12 mm diameter); for the primary coil, the wire was wound 150 times around the plastic container; for the two secondary coils, the wire was wound 33 times around every layer to correct the uneven distribution of the magnetic flux density of the primary coil; a plastic incubator (25 cm length, 20 cm width and 10 cm height) containing the culture dishes was placed in the middle of each plastic container; to maintain the temperature of 37 ± 0.5°C and 5% CO2 in the incubator, warm water (40 ± 0.5°C) and 5% CO2 air were supplied in the container; the temperature difference between ELF-MF and sham exposure apparatuses was maintained within ± 0.5°C
Sham exposure A sham exposure was conducted.
Additional info sham exposure was performed simultaneously with exposure using a sham apparatus, which was made using the same materials with the same size, except for the coil
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.5 mT - measured - -
Additional parameter details

background ELF magnetic flux density was 40-50 µT and static magnetic flux density was 25-30 µT in apparatuses

Exposure 2

Main characteristics
Frequency 60 Hz
Type
Exposure duration for 24 hours
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.25 mT - measured - -

Exposure 3

Main characteristics
Frequency 60 Hz
Type
Exposure duration for 24 hours
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.5 mT - measured - -

Exposure 4

Main characteristics
Frequency 60 Hz
Type
Exposure duration for 24 hours
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 3 mT - measured - -

Reference articles

  • Soda A et al. (2008): Effect of exposure to an extremely low frequency-electromagnetic field on the cellular collagen with respect to signaling pathways in osteoblast-like cells

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Exposure to the magnetic field was found to significantly increase the secretion of corticosterone and aldosterone and the gene expression and/or protein expression of Cyp11a1 and Cyp11b2 in mouse Y-1 cells compared to the control group. It was also found that only a magnetic flux density of 0.5 mT or more could induce a significant increase in corticosterone secretion in exposed Y-1 cells compared to the control group.
Exposed Y-1 cells showed significant decreases in phosphodiesterase enzyme activity and intracellular calcium concentration and significant increases in cAMP concentration and CREB phosphorylation compared to cells of the control group. The increase in cAMP concentration was not inhibited by treatment with NF449, suggesting that it did not result from an activation of G protein-coupled receptors.
No effects were found in human adrenal cortex-derived cells.
The authors conclude that exposure of mouse adrenal cortex-derived cells to a 60 Hz magnetic field might stimulate the steroid hormone production via an increase in intracellular cAMP caused by the inhibition of phosphodiesterase enzyme activity.

Study character:

Study funded by

Related articles