Study type: Medical/biological study (experimental study)

Prolonged Ca2+ transients in ATP-stimulated endothelial cells exposed to 50 Hz electric fields. med./bio.

Published in: Cell Biol Int 2005; 29 (3): 237-243

Aim of study (acc. to author)

To study the effects of 50 Hz extremely low frequency electric fields on intracellular Ca2+ peak levels and on the duration of Ca2+ transients using Fluo3 fluorescence in individual human umbilical vein endothelial cells stimulated by ATP.

Background/further details

To ascertain whether the influence of the electric fields on the Ca2+ signal was related to the release of Ca2+ from intracellular stores, the effects of an inositol triphosphate receptor inhibitor (xestospongin C, 10 µM) were also investigated.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 24 h
Exposure 2: 50 Hz
Exposure duration: continuous for 24 h

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 24 h
Exposure setup
Exposure source
  • parallel stainless steel plates, 10 cm apart
Chamber CO2 incubator
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 30 mV/m - - - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 24 h
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 300 V/cm - - - corresponding induced current density in the medium was 0.42 mA/m²

Reference articles

  • Takahashi K et al. (2002): Effects of low-frequency electric fields on the intracellular Ca2+ response induced in human vascular endothelial cells by vasoactive substances

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Alterations in intracellular calcium concentration induced by ATP-stimulation in the absence of extracellular Ca2+ were revealed in individual cells. No differences were found between the exposure and sham-exposure groups in intracellular calcium concentration resting level before ATP-stimulation, or in the intracellular calcium concentration peak levels induced by stimulation. However, the duration of the initial transients in intracellular calcium concentration following an ATP stimulus was significantly prolonged by exposure to a 30 kV/m field.
The inositol trisphosphate receptor inhibitor inhibited the ATP-induced elevation in intracellular calcium concentration in both the exposure and sham exposure groups. The ATP-receptor P2Y appeared to play an important role in the increase of intracellular calcium concentration.
The data indicate that an extremely low frequency electric field affects the function of vascular endothelial cells by a mechanism involving activation of P2Y.

Study character:

Study funded by

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