Study type: Medical/biological study (experimental study)

Electromagnetic fields instantaneously modulate nitric oxide signaling in challenged biological systems. med./bio.

Published in: Biochem Biophys Res Commun 2012; 426 (3): 330-333

Aim of study (acc. to author)

To examine the effect of a non-thermal pulsed electromagnetic field on the release of nitric oxide in neuronal cells chellenged with lipopolisaccharides (LPS) and the involvement of calcium/calmodulin as a response to such a field in fibroblasts.

Background/further details

Several cellular, animal and clinical studies, using electromagnetic signals have reported significant effects on tissue repair, angiogenesis, pain and inflammation. To further understand these mechanisms, two experimants were performed:
For the first experiment, neuronal cells were taken out of the incubator (37°C) and the culture medium was replaced with saline (23°C). Hence, cells were challenged through heat shock and low serum. After three minutes, a non toxic concentration of lipopolysaccharides was added to the cells. The electromagnetic field was turned on two minutes prior to the introduction of lipopolysaccharides. Nitric oxide was measured electrochemically in real-time.
For the second experiment, fibroblasts cultures, containing calf serum (increases cytosolic Ca2+ concentration) were allowed to grow in an incubator for 24 h. Three hours prior to electromagnetic field exposure, the calmodulin antagonist W-7 was added at different concentrations. After a 15 minutes exposure, nitric oxide was measured.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 27.12 MHz
Modulation type: pulsed
Exposure duration: 2 min prior to LPS administration
MN9D cells
Exposure 2: 27.12 MHz
Modulation type: pulsed
Exposure duration: continuous for 15 min

Exposure 1

Main characteristics
Frequency 27.12 MHz
Type
Exposure duration 2 min prior to LPS administration
Additional info MN9D cells
Modulation
Modulation type pulsed
Pulse width 2 ms
Repetition frequency 2 Hz
Exposure setup
Exposure source
Setup single turn coil with a diameter of 20 cm; a) for studies at 37°C: coil placed inside an incubator equipped with a single plastic shelf b) for studies at 23 ± 1°C: coil placed on a non-metallic laboratory bench
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2.5 µT peak value measured - in the middle of a plane 1 cm from the coil's surface
electric field strength 41 V/m mean measured - ± 10 V/m in the cells at the bottom of a 35 mm petri dish

Exposure 2

Main characteristics
Frequency 27.12 MHz
Type
Exposure duration continuous for 15 min
Additional info fibroblasts
Modulation
Modulation type pulsed
Pulse width 2 ms
Repetition frequency 2 Hz
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2.5 µT peak value measured - in the middle of a plane 1 cm from the coil's surface
electric field strength 41 V/m mean measured - ± 10 V/m in the cells at the bottom of a 35 mm petri dish

Reference articles

  • Pilla A et al. (2011): Electromagnetic fields as first messenger in biological signaling: Application to calmodulin-dependent signaling in tissue repair.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Regarding the first experiment, the release of nitric oxide after administration of an acute non-toxic concentration of lipopolysaccharide was approximately three-fold higher in exposed neuronal cells than in control cells.
In the second experiment, the release of nitric oxide was increased approximately two-fold in exposed samples compared to control samples. This effect was blocked by the calmodulin antagonist W-7.
The authors conclude that the experimental results reported in this study provide support for calcium/calmodulin-dependent nitric oxide production as an important mediator of electromagnetic field signaling that may explain the observed effects of electromagnetic fields on tissue repair, angiogenesis, pain and inflammation in animal models and clinical studies.

Study character:

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