Study type: Medical/biological study (experimental study)

Pulsed electric field exposure of insulin induces anti-proliferative effects on human hepatocytes. med./bio.

Published in: Bioelectromagnetics 2005; 26 (8): 639-647

Aim of study (acc. to author)

To study the effects and the mechanism of a pulsed electric field on insulin and its subsequent mediation of proliferative changes in human hepatocytes in vitro.

Background/further details

Insulin solution was exposed to pulsed electromagnetic field and added to the culture medium of hepatocytes. Insulin is usually added into the culture medium to accelerate cell growth.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 kHz
Modulation type: pulsed
Exposure duration: continuous for 10 min, 20 min and 40 min

Exposure 1

Main characteristics
Frequency 50 kHz
Type
Waveform
Exposure duration continuous for 10 min, 20 min and 40 min
Modulation
Modulation type pulsed
Pulse width 20 µs
Rise time 12 µs
Repetition frequency 50 Hz
Exposure setup
Exposure source
Setup 96-well micro-plate containing insulin stock solution was placed between the two plates, which were 16 mm apart.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 7.1 V/m maximum estimated - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Pulsed electric fields produced a conformational change of insulin molecule. The binding capacity of insulin to its receptors was reduced to 87% of the control level after pulsed electric field exposure. The average intracellular tyrosine phosphorylation level decreased by 11%. The expression of 55 of 12000 genes investigated was modified, including an increase in the expression of human tyrosine phosphatase and the small GTP-binding protein.
Based on these data, a mechanism is proposed to explain the biological effects of pulsed electric fields on hepatocyte proliferation through the insulin signaling pathway.

Study character:

Study funded by

Related articles