Medical/biological study (experimental study)

Age-Dependent Effects of ELF-MF on Oxidative Stress in the Brain of Mongolian Gerbils med./bio.

By: Selakovic V, Raus Balind S, Radenovic L, Prolic Z, Janac B

Published in: Cell Biochem Biophys 2013; 66 (3): 513-521

Aim of study (acc. to author)

To study the effects of extremely low frequency magnetic fields on oxidative stress in the brain of adult (3 months old) and middle-aged (10 month old) gerbils.

Background/further details

Groups of four gerbils per cage were used: cage control, sham exposed group and three different exposure groups. The gerbils from sham exposed and exposed groups were subdivided into two groups, one sacrificed on the 7^th day (immediately after the exposure) and the other one sacrificed on the 10^th day from the beginning of the experiment.

Endpoint

effects on the neurological system: oxidative stress in different brain regions (forebrain cortex, striatum, hippocampus, and cerebellum)

Exposure

- 50 Hz
- 50/60 Hz
- magnetic field
- low frequency

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: continuous for 7 days	magnetic flux density: 8.9 mT maximum (on the electromagnetic poles) magnetic flux density: 0.5 mT average over time (in the cages) magnetic flux density: 0.25 mT average over time (in the cages) magnetic flux density: 0.1 mT average over time (in the cages)

General information

Animals were exposed at three different magnetic flux densities.

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 7 days

Exposure setup

Exposure source	elctromagnet
Setup	electromagnet with a regular laminated transformer core and a pole diameter of 9.5 cm; gerbils placed in 26 cm x 43 cm x 15 cm polycarbonate cages; two cages with 3-4 gerbils positioned simultaneously near the magnet, one on the left and the other on the right side with a distance between 20 cm and 40 cm
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	8.9 mT	maximum	measured	-	on the electromagnetic poles
magnetic flux density	0.5 mT	average over time	measured	-	in the cages
magnetic flux density	0.25 mT	average over time	measured	-	in the cages
magnetic flux density	0.1 mT	average over time	measured	-	in the cages

Additional parameter details

magnetic force lines parallel to the horizontal component of the geomagnetic field

Reference articles

Janac B et al. (2012): Temporal patterns of extremely low frequency magnetic field-induced motor behavior changes in Mongolian gerbils of different age
Nikolic LM et al. (2010): Effect of alternating the magnetic field on phosphate metabolism in the nervous system of Helix pomatia

Exposed system:

animal
Mongolian gerbils (Meriones unguiculatus)
whole body

Methods Endpoint/measurement parameters/methodology

effects on the neurological system: oxidative stress in different brain regions (nitric oxide level, superoxide production, superoxide dismutase enzyme activity, lipid peroxidation (via thiobarbituric acid reactive substances); spectrophotometry)

Investigated system:

brain homogenates and supernatants

Investigated organ system:

brain/CNS

Time of investigation:

after exposure

Main outcome of study (acc. to author)

In all gerbils, extremely low frequency magnetic field exposure significantly increased oxidative stress in all investigated brain regions. This effect increased in a magnetic flux density intensity dependent manner and was higher in middle-aged gerbils. Three days after exposure termination, the values of oxidative stress parameters showed a tendency to return to their control levels, particularly in 3-month-old gerbils.
These findings indicate that an extremely low frequency magnetic field exposure is able to induce oxidative stress in the brain of gerbils in an age- and magnetic field intensity-dependent manner.

Study character:

medical/biological study
experimental study
full/main study
blind study

Study funded by

Military Medical Academy (MMA), Serbia
Ministry of Education, Science and Technological Development, Serbia

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