Study type: Medical/biological study (experimental study)

Extremely Low Frequency Magnetic Field (50 Hz, 0.5 mT) Reduces Oxidative Stress in the Brain of Gerbils Submitted to Global Cerebral Ischemia. med./bio.

Published in: PLoS One 2014; 9 (2): e88921

Aim of study (acc. to author)

To investigate whether extremely low frequency magnetic fields influence oxidative stress in the brain of gerbils submitted to global cerebral ischemia.

Background/further details

Gerbils were submitted to 10 minutes of global cerebral ischemia by occlusion of both carotid arteries. Afterwards, animals were exposed to an extremely low frequency magnetic field for 7 days and examined either directly after the exposure (7. experimental day, immediate effect of exposure) or 7 days later (14. experimental day, delayed effects of exposure).
The following groups were examined: 1.) cage control (n=6), 2.) sham operated without ischemia (n=6), 3.) sham exposed (n=6), 4.) exposure (n=13), 5.) ischemia (n=12) and 6.) ischemia + exposure (n=13).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 7 days

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 7 days
Exposure setup
Exposure source
Setup electromagnet was placed in an isolated room with same conditions as vivarium (temperature 23 ± 2°C; humidity 55 ± 10%; lights on for 12 hours daily (7-19 Uhr))
Sham exposure A sham exposure was conducted.
Additional info geomagnetic activity was characterized as "very quiet" (measured by the Department of Geomagnetism and Aeronomy, Serbia)
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 0.5 mT - - - -

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:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

No differences were found between the cage control, sham operated and sham exposed group. Hence, these gerbils were considered as the only control group (n= 8).
In all examined brain areas of gerbils submitted to ischemia, oxidative stress parameters were significantly increased on the 7. and 14. experimental day compared to the control group. In magnetic field-exposed gerbils, oxidative stress parameters were significantly increased compared to the control group on the 7. day, but not on the 14. day. Ischemic gerbils that were exposed had significantly increased oxidative stress levels on the 7. day compared to the control, but to a lesser extent than gerbils submitted to ischemia or magnetic field-exposure alone. However, on the 14. experimental day, oxidative stress parameters from gerbils of this group were similar to the parameters of the control group.
Summarized, magnetic field-exposure or submission to cerebral ischemia alone led to an increase in the oxidative stress levels in the brain of gerbils, while a combination of both treatments diminished the effect. The authors conclude that the results could indicate a beneficial effect of extremely low frequency magnetic fields in the management of global cerebral ischemia.

Study character:

Study funded by

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