Medical/biological study (experimental study)

Study on gap junctional intercellular communication inhibition by ELF magnetic fields using FRAP method med./bio.

By: Hu GL, Fu YD, Zeng QL, Xu ZP, Chiang H

Published in: Electromagn Biol Med 2002; 21 (2): 155-160

Aim of study (acc. to author)

To study the effects of 50 Hz magnetic fields on gap junctional intercellular communication with fluorescence recovery after photobleaching (FRAP).

Background/further details

The study is an extension of a previous study (publication 387). The effects of magnetic fields at different intensities (alone or combined with 5 ng/ml TPA) were investigated.

Endpoint

cell function: gap junctional intercellular communication

Exposure

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: continuous for 24 h	magnetic flux density: 0.1 mT magnetic flux density: 0.2 mT magnetic flux density: 0.4 mT magnetic flux density: 0.8 mT

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 24 h

Exposure setup

Exposure source	Three groups of 36 cm² copper coils
Chamber	Incubator
Setup	Culture dishes placed coaxially to the centerline in the center area of the coils.
Additional info	MF perpendicular to the diameter of the dishes.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	0.1 mT	-	measured	unspecified	-
magnetic flux density	0.2 mT	-	measured	unspecified	-
magnetic flux density	0.4 mT	-	measured	unspecified	-
magnetic flux density	0.8 mT	-	measured	unspecified	-

Additional parameter details

AC background field was 1-2 µT. Static geomagnetic field was 18.5 µT with 14.1 µT horizontal and 12.0 µT vertical components.

Exposed system:

intact cell/cell culture
CHL (Chinese hamster lung) cells

Methods Endpoint/measurement parameters/methodology

cell function: gap junctional intercellular communication (fluorescence recovery after photobleaching (FRAP))

Investigated system:

intact cell/cell culture

Time of investigation:

after exposure

Main outcome of study (acc. to author)

The data indicated that the FRAP technique used in this study was more sensitive in detecting changes of gap junctional intercellular communication inhibition than dye transfer assay used in the previous study. The threshold level was 0.4 mT for gap junctional intercellular communication suppression by 50 Hz magnetic fields. Additionally, 0.2 mT (or more than 0.2 mT) magnetic fields can enhance the inihibition of gap junctional intercellular communication induced by TPA.
The authors conclude that magnetic fields may act as a cancer promoter or work in synergy with other cancer promoters.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

National Natural Science Foundation (NSFC), China

Percherancier Y et al. (2015): Effects of 50 Hz magnetic fields on gap junctional intercellular communication in NIH3T3 cells
Zeng Q et al. (2006): Noise magnetic fields abolish the gap junction intercellular communication suppression induced by 50 Hz magnetic fields
Sul AR et al. (2006): Effects of sinusoidal electromagnetic field on structure and function of different kinds of cell lines
Somosy Z et al. (2004): Alteration of tight and adherens junctions on 50-Hz magnetic field exposure in Madin Darby canine kidney (MDCK) cells
Zeng QL et al. (2003): ELF magnetic fields induce internalization of gap junction protein connexin 43 in Chinese hamster lung cells
Ye J et al. (2002): Changes in gap junctional intercellular communication in rabbits lens epithelial cells induced by low power density microwave radiation
Li CM et al. (1999): Effects of 50 Hz magnetic fields on gap junctional intercellular communication