Medical/biological study (experimental study)

Melatonin modulates wireless (2.45 GHz)-induced oxidative injury through TRPM2 and voltage gated Ca(2+) channels in brain and dorsal root ganglion in rat.

Published in: Physiol Behav 2012; 105 (3): 683-692

Aim of study (acc. to author)

To investigate the effects of a 2.45 GHz electromagnetic field exposure on the brain cortex and the dorsal root ganglion of rats, as well as the possible protective effects of melatonin administration.
Background/further details: 4 groups (n=8 per group) were examined: 1.) cage control, 2.) sham exposure + daily injection of saline, 3.) exposure and 4.) exposure + daily injection of melatonin (10 mg/kg).
Before the animals were killed, an EEG was recorded. Afterwards, brain homogenates and the dorsal root ganglion were investigated for signs of oxidative stress. Additionally, in the dorsal root ganglion, the intracellular calcium concentration was determined and the patch-clamp technique was conducted.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Exposure duration: continuous for 1 h/day on 30 days
General information
Rats were treated in the following four groups: i) cage control ii) sham exposure iii) EMF exposure iv) EMF exposure + melatonin administration (10 mg/kg per day)
Exposure 1
Main characteristics
Frequency 2.45 GHz
Type
Exposure duration continuous for 1 h/day on 30 days
Exposure setup
Exposure source/structure
Distance between exposed object and exposure source 1 m
Setup details rats kept in 15 cm long cylindrical constrainers with a diameter of 5 cm; 8 constrainers positioned radially on a groundplate with the antenna in the center; rats placed with their heads near the antenna
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Remarks
electric field strength 11 V/m - measured -
power density density 1 mW/m² - - -
SAR 0.143 W/kg - calculated at the rat's head with E = 10 V/m d: am Kopf der Ratte bei
SAR 0.1 W/kg spatial average calculated -
Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

In general, no differences were found between the cage control (group 1) and the sham exposed group (group 2).
In the exposed group (group 3), the number of spikes in the EEG was increased compared to the control groups (group 1+2). However, no differences occurred in the EEG between the exposed group treated with melatonin (group 4) and the control groups (groups 1+2).
In the dorsal root ganglia of exposed rats (group 3), the cell viability was significantly decreased compared to the control groups (group 1+2). In contrast, there was no difference in the cell viability between the melatonin treated exposure group (group 4) and the control groups (groups 1+2). Additionally, in the exposed group (group 3), the level of lipid peroxidation and the intracellular calcium release were increased in comparison to the control groups (groups 1+2). Again, no differences in the level of lipid peroxidation and the intracellular calcium release were found between the melatonin treated exposure group (group 4) and the control groups (group 1+2). The current densities of the neurons were higher in the exposed group (group 3) than in the control groups (groups 1+2).
In brain homogenates of exposed rats, treated with melatonin (group 4), an increased concentration of vitamin E was found, whereas the concentration of vitamin E in the other groups (groups 1+2+3) did not change.
Remaining brain homogenate and dorsal root ganglion antioxidant values were not affected by exposure or melatonin administration.
The authors conclude that exposure to a wireless device of 2.45 GHz could induce oxidative stress in the dorsal root ganglion and that melatonin could prevent such a reaction.
Study character:
  • medical/biological study
  • experimental study
  • full/main study

Study funded by

  • Suleyman Demirel University, Turkey

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