Study type: Medical/biological study (experimental study)

The Effects of Single and Repeated Exposure to 2.45 GHz Radiofrequency Fields on c-Fos Protein Expression in the Paraventricular Nucleus of Rat Hypothalamus. med./bio.

Published in: Neurochem Res 2011; 36 (12): 2322-2332

Aim of study (acc. to author and editor)

To study the effects of radiofrequency exposure resulting in non-thermal (< 4 W/kg) specific absorption rates on c-Fos expression in the paraventricular nucleus (of the hypothalamus) of rats.

Background/further details

60 female rats were divided into the following groups: 1) 20 rats were divided into three subgroups and exposed at 0, 3 and 12 W for 30 min. The rats were killed 90 min following exposure (when maximum c-Fos protein expression occurs). 2) 20 rats were divided into three subgroups and exposed at 0, 3 and 12 W for 30 min. The rats were killed 24 h following exposure. 3) 20 rats were exposed at 3 W for 30 min per day for a total of ten times in a two week period.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Exposure duration: continuous for 30 min
Exposure 2: 2.45 GHz
Exposure duration: continuous for 30 min/day on 10 times during 2 weeks
Exposure 3: 2.45 GHz
Exposure duration: continuous for 30 min

Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration continuous for 30 min
Exposure setup
Exposure source
Setup rat immobilized in a methacrylate cylinder placed in the area of maximum field uniformity in the GTEM cell
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 3 W - - - -
electric field strength 40.28 V/m - - - -
SAR 0.0776 W/kg mean calculated brain -
SAR 0.041 W/kg mean calculated whole body -
SAR 0.22 W/kg peak value calculated 1 g brain
SAR 0.203 W/kg peak value calculated 1 g whole body

Exposure 2

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration continuous for 30 min/day on 10 times during 2 weeks
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 3 W - - - -
electric field strength 40.28 V/m - - - -
SAR 0.0776 W/kg mean calculated brain -
SAR 0.041 W/kg mean calculated whole body -
SAR 0.22 W/kg peak value calculated 1 g brain
SAR 0.203 W/kg peak value calculated 1 g whole body

Exposure 3

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration continuous for 30 min
Exposure setup
Exposure source
Setup rat immobilized in a methacrylate cylinder placed in the area of maximum field uniformity in the GTEM cell
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 12 W - - - -
electric field strength 80.56 V/m - - - -
SAR 0.301 W/kg mean calculated brain -
SAR 0.16 W/kg mean calculated whole body -
SAR 0.901 W/kg peak value calculated 1 g brain
SAR 0.791 W/kg peak value calculated 1 g whole body

Reference articles

  • Jorge-Mora T et al. (2010): Exposure to 2.45 GHz microwave radiation provokes cerebral changes in induction of HSP-90 a/ß.heat shock protein in rat.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

A high SAR value induced an increase of the c-Fos expression 90 min or 24 h after exposure, and a low SAR value resulted in higher c-Fos expression than in control rats after 24 h. Repeated irradiation at 3 W increased cellular activation of the paraventricular nucleus by more than 100% compared to animals subjected to acute exposure or to repeated sham exposed animals.
The data suggest that the paraventricular nucleus is sensitive to 2.45 GHz microwave exposure at non-thermal SAR levels.

Study character:

Study funded by

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