Study type: Medical/biological study (experimental study)

Evaluation of inflammatory biomarkers associated with oxidative stress and histological assessment of magnetic therapy on experimental myopathy in rats. med./bio.

Published in: Electromagn Biol Med 2012; 31 (4): 320-332

Aim of study (acc. to author)

The effects of exposure of myopathy model-rats to a pulsed magnetic field (50 Hz carrier frequency) on inflammatory processes and oxidative stress in the blood and in the muscle should be investigated.

Background/further details

Myopathy is a muscular disease, characterized by muscular weakness. Myopathy model rats were created by an injection of carrageenan alpha (50 µl, 1%) into the hind paw 24 hours prior to the start of exposure. Pulsed magnet fields are already used in the therapy of inflammatory diseases, however, there is still a lack of scientific evidence on their efficacy.
Rats were divided into the following groups (n=10 each): 1) exposure of healthy rats to the pulsed magnetic field, 2) sham exposure of healthy rats, 3) sham exposure of myopathy model rats investigated after 24 h, 4) sham exposure of myopathy model rats, and 5) exposure of myopathy model rats to the pulsed magnetic field. Except for group 3, all groups were investigated after 8 days.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Modulation type: pulsed
Exposure duration: continuous for 30 min/day for 8 days

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 30 min/day for 8 days
Modulation
Modulation type pulsed
Pulse width 640 ms
Repetition frequency 0.78 Hz
Additional info

carrier signal: 50 Hz biphasic truncated sinusoidal waveform (Amplitude Shift Keying) modulating signal: square waveform amplitude (root mean square): 18.6 V; peak to peak voltage: 68.8 V

Exposure setup
Exposure source
Chamber transparent vinyl cylinder
Setup two circular solenoid disks (each 12 cm in diameter and 1.8 cm thick), separated by 15 cm, placed inside the transparent vinyl cylinder; rat was placed on lower disk inside the cylinder
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 20 mT - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

All parameters were significantly increased in sham exposed myopathy model rats (groups 3 and 4) compared to exposed (group 1) and sham exposed (group 2) healthy rats. However, exposure of myopathy model rats (group 5) reduced these values and there were no significant differences compared to healthy rats (groups 1 and 2) anymore.
The authors conclude that exposure to a pulsed magnetic field (50 Hz carrier frequency) could decrease inflammatory processes and oxidative stress in myopathy model-rats.

Study character:

Study funded by

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