Study type: Medical/biological study (experimental study)

Elf-pulsed magnetic fields modulate opioid peptide gene expression in myocardial cells. med./bio.

Published in: Cardiovasc Res 2000; 45 (4): 1054-1064

Aim of study (acc. to author)

To investigate the effects of extremely low frequency (ELF) pulsed magnetic fields (PMF) on opioid peptide gene expression and the signaling pathway controlling the corresponding gene transcription in rat myocardial cells.

Background/further details

Ventricular cardic myocytes were isolated from male Wistar rats.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Modulation type: pulsed
Exposure duration: 0.5 h, 1 h, 4 h or 8 h

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
  • sawtooth-shaped
Exposure duration 0.5 h, 1 h, 4 h or 8 h
Modulation
Modulation type pulsed
Rise time 1.34 ms
Exposure setup
Exposure source
Setup a pair of rectangular coils in a pseudo Helmholtz configuration
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.74 mT peak value unspecified - -
electric field strength 2 mV/m maximum estimated - induced electric field at the inner walls of the culture dish

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The mRNA level of the opioid peptide prodynorphin was found to be markedly increased in PMF exposed myocytes. A direct PMF exposure of isolated nuclei leads to an increased prodynorphin mRNA level as well. Prodynorphin gene transcription could not be affected by nuclear PMF exposure in the presence of specific protein kinase C (PKC) inhibitores. This effect was found to be independent of PKC isoenzymes and their cellular distribution. Synthesis and secretion of dynorphin B, another opioid peptid, was also increased by PMF exposure.

Study character:

Study funded by

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