Study type: Medical/biological study (experimental study)

Stimulation of phagocytosis and free radical production in murine macrophages by 50 Hz electromagnetic fields. med./bio.

Published in: Eur J Cell Biol 2001; 80 (8): 562-566

Aim of study (acc. to author)

To study the activating capacity of 50 Hz electromagnetic fields by investigating phagocytosis and free radical production in mouse bone marrow-derived macrophages. To study whether protein kinase C-mediated signal transduction pathway is involved, co-exposures with TPA and electromagnetic fields were performed.

Background/further details

TPA stimulation (1 nM, 10 nM and 1 mM) was used as positive control for macrophage activation, because both phagocytic activity as well as radical production can be stimulated by TPA. TPA interacts with protein kinase C and is able to activate protein kinase C-mediated signal transduction.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 30, 45 and 60 min

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 30, 45 and 60 min
Exposure setup
Exposure source
Setup Culture dishes were placed in the center of the exposure system in a tissue culture incubator. Control samples were either run simultaneously in a separate incubator or in the same incubator with the coil system switched off.
Additional info Two different exposure systems, Merritt coil system and Helmholtz coil system, were used to generate horizontally polarized magnetic fields with respect to the culture medium surface.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.5 mT maximum measured - 1.0 mT or 0.5 mT

Reference articles

  • Simko M et al. (1998): Micronucleus formation in human amnion cells after exposure to 50 Hz MF applied horizontally and vertically.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Short-time exposure (45 min) to electromagnetic fields resulted in significantly increased phagocytic uptake. Stimulation with TPA (1 nM) showed the same increased phagocytic activity as 1 mT electromagnetic fields. However, co-exposure to electromagnetic fields and TPA showed no further increase of bead uptake. Therefore the authors concluded that because of the absence of additive effects, the electromagnetic fields-induced stimulation of these macrophages does not involve the protein kinase C signal transduction pathway.
Furthermore, a significant increased superoxide production after electromagnetic field exposure was detected. This is taken for evidence of direct activation of macrophages.

Study character:

Study funded by

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