Medical/biological study (experimental study)

Effect of exposure to 1,800 MHz electromagnetic fields on heat shock proteins and glial cells in the brain of developing rats med./bio.

By: Watilliaux A, Edeline JM, Leveque P, Jay TM, Mallat M

Published in: Neurotox Res 2011; 20 (2): 109-119

Aim of study (acc. to author)

To study whether GSM 1800 MHz electromagnetic fields affect immature rodent brains when applied at various stages of postnatal development.

Background/further details

Young rats, exposed to electromagnetic fields on postnatal days 5 (n=6), 15 (n=5) or 35 (n=6), were compared to sham exposed littermate rats (n=6 at all ages).

Endpoint

effects on the neurological system: stress reaction and glial activation in the immature brain

Exposure

- mobile communications
- GSM

Exposure	Parameters
Exposure 1: 1,800 MHz Modulation type: pulsed Exposure duration: continuous for 2 h on postnatal day 5, 15 or 35	SAR: 0.13 W/kg mean (whole body) (on postnatal day 35) SAR: 0.63 W/kg mean (whole body) (on postnatal day 15) SAR: 1.2 W/kg mean (whole body) (on postnatal day 5) SAR: 1.7 W/kg mean (brain) (on postnatal day 35) SAR: 2.2 W/kg mean (brain) (on postnatal day 15) SAR: 2.5 W/kg mean (brain) (on postnatal day 5)

Exposure 1

Main characteristics

Frequency	1,800 MHz
Type	electromagnetic field
Exposure duration	continuous for 2 h on postnatal day 5, 15 or 35

Modulation

Modulation type	pulsed
Duty cycle	12.5 %
Repetition frequency	217 Hz

Exposure setup

Exposure source	loop antenna
Setup	loop antenna consisting of a printed circuit with two metallic lines engraved in a dielectric epoxy resin substrate with a 1 mm wide line forming loop at one end, which was placed close to the animal's head
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	0.13 W/kg	mean	calculated	whole body	on postnatal day 35
SAR	0.63 W/kg	mean	calculated	whole body	on postnatal day 15
SAR	1.2 W/kg	mean	calculated	whole body	on postnatal day 5
SAR	1.7 W/kg	mean	calculated	brain	on postnatal day 35
SAR	2.2 W/kg	mean	calculated	brain	on postnatal day 15
SAR	2.5 W/kg	mean	calculated	brain	on postnatal day 5

Reference articles

Leveque P et al. (2004): Dosimetric Analysis of a 900-MHz Rat Head Exposure System
Dubreuil D et al. (2003): Head-only exposure to GSM 900-MHz electromagnetic fields does not alter rat's memory in spatial and non-spatial tasks
Dubreuil D et al. (2002): Does head-only exposure to GSM-900 electromagnetic fields affect the performance of rats in spatial learning tasks?

Exposed system:

animal
rat/Wistar
partial body: head (mainly)

Methods Endpoint/measurement parameters/methodology

effects on the neurological system: stress reaction and glial activation in the immature brain (expression of heat shock proteins (Hsp60, Hsc70, Hsp70, Hsp90) and expression of GFAP, serine racemase, two glutamate transporters (GLT1 and GLAST) and CD68; Western blot); glial activation (expression of CD68 and CD11; immunocytochemistry)

Investigated system:

isolated bio./chem. substance
tissue slices
brain tissue homogenates and lysates

Investigated organ system:

brain/CNS

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The GSM signal had no significant effect on the abundance of Hsp60, Hsc70 or Hsp90, of serine racemase, glutamate transporters (GLT1 and GLAST), or of GFAP. Immunohistochemical detection of CD68 antigen in brain sections from sham exposed and exposed animals did not reveal any differences in the morphology or distribution of microglial cells.
These data provide no evidence for acute cell stress or glial reactions indicative of early neural cell damage in developing brains exposed to 1800 MHz signals.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Centre National de la Recherche Scientifique (CNRS; French National Center for Scientific Research), France
Fondation Santé et Radiofréquences, France
Institut National de L'Environnement Industriel et des Risques (INERIS), France
Institut national de la santé et de la recherche médicale (INSERM), France
Université Pierre et Marie Curie (UPMC), Paris, France

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