Study type: Medical/biological study (experimental study)

Membrane permeabilization and cell damage by ultrashort electric field shocks med./bio.

By: Pakhomov AG, Shevin R, White JA, Kolb JF, Pakhomova ON, Joshi RP, Schoenbach KH
Published in: Arch Biochem Biophys 2007; 465 (1): 109-118
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Aim of study (acc. to author)

This study was undertaken to analyze the effects of nanosecond pulsed electric fields exposure on cell membrane permeabilization in mural and human cells in vitro.

Background/further details

The effects of pulsed electric fields exposure on the mural and human cells were investigated in four different ion milieus and by the use of propidium iodide. The uptake of the fluorescent dye propidium iodide into the cell was measured as it is a sensitive marker of cell membrane integrity. The occurence of this dye in the cell indicates loss of membrane integrity. In this way mechanisms of changed membrane permeabilization under exposure to nanosecond pulsed electric fields should be further characterized.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 10–50 kHz
Modulation type: pulsed
Exposure duration: up to 200 pulses

Exposure 1

Main characteristics
Frequency 10–50 kHz
Type
Waveform
Exposure duration up to 200 pulses
Modulation
Modulation type pulsed
Pulse width 60 ns
Pulse type rectangular
Exposure setup
Exposure source
  • pair of tungsten electrodes with a diameter of 0.125 mm each and a gap of 0.31 mm
Distance between exposed object and exposure source 5 µm
Setup cells placed in the middle of the electrode gap
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 12 kV/cm - calculated - -
cf. remarks - - calculated - U = 540 - 580 V

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

After short nanosecond pulsed electric fields exposure an increase in membrane conductance was observed in the cells and necrotic changes appeared after the exposure to long nanosecond pulsed electric fields. Both parameters were cell type-dependent. They were much weaker in human cervical carcinoma cells than in murine pituitary cells.
No propidium iodide uptake was observed by either cell line. Lanthanum and gadolinium ions significantly inhibited the nanosecond pulsed electric fields-induced membrane conductance increase, and protected the exposed cells from developing necrosis.

Study character:

Study funded by

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