Study type: Medical/biological study (experimental study)

Effects of Universal Mobile Telecommunications System (UMTS) electromagnetic fields on the blood-brain barrier in vitro. med./bio.

Published in: Radiat Res 2005; 164 (3): 258-269

Aim of study (acc. to author)

Investigation on the influence of a generic UMTS (Universal Mobile Telecommunications System) signal on barrier tightness, transport processes and the morphology of porcine brain microvascular endothelial cell cultures serving as an in vitro model of the blood-brain barrier.

Background/further details

Response of the cells to thermal stress was also investigated (with elevated temperatures of 37.3 - 39°C).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.966 GHz
Exposure duration: continuous for 1 up to 3.5 days

Exposure 1

Main characteristics
Frequency 1.966 GHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 1 up to 3.5 days
Exposure setup
Exposure source
Chamber Two radial waveguides each containing up to 28 samples were placed into an incubator and were used in turns as the exposure device or sham-exposure device. The samples in each waveguide were arranged symmetrically near the rim. The reflections were reduced by a 5-mm flat absorber along the waveguide perimeter.
Setup The filters carrying the cell cultures were installed in cylindrical tubes between two discoid gold electrodes. Each sample holder was equipped with a two-electrode system for impedance monitoring. The leads of the electrodes were conducted upward through the metal caps that sealed the cartridges. Thus simultaneous RF-field exposure and LF impedance measurement was possible.
Additional info The barrier tightness was monitored continuously by TEER measurement using impedance spectroscopy described in detail by Wegener et al. in Brain Res. 853, 115-124 (2000). Impedance analysis was carried out in the frequency range from 1 Hz to 500 kHz applying a sinusoidal voltage of ~30 mV amplitude.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 34 V/m mean measured and calculated - ± 40% SD
SAR 1.64 W/kg average over mass calculated cf. remarks vessel with 3.5 ml solution
electric field strength 10.8 V/m mean measured and calculated - -
electric field strength 3.4 V/m mean measured and calculated - -

Reference articles

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

No evidence of radiofrequency-field-induced disturbance of the function of the blood-brain barrier was found. After and during exposure, the tightness of the blood-brain barrier quantified by 14C-sucrose permeation as well as by trans-endothelial electrical resistance remained unchanged compared to sham-exposed cultures. Permeation of transporter substrates at the blood-brain barrier as well as the localization and integrity of the tight junction proteins occludin and ZO1 were not affected either.

Study character:

Study funded by

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