Medical/biological study (experimental study)

Calcium efflux of plasma membrane vesicles exposed to ELF magnetic fields--test of a nuclear magnetic resonance interaction model med./bio.

By: Sun WJ, Mogadam MK, Sommarin M, Nittby H, Salford LG, Persson BR, Eberhardt JL

Published in: Bioelectromagnetics 2012; 33 (7): 535-542

Aim of study (acc. to author)

To study the effects of extremely weak 60 Hz magnetic fields on the transport of Ca²⁺ in a biological system consisting of highly purified plasma membrane vesicles.

Background/further details

The authors tested a proposed quantum mechanical model postulating that magnetic field induced polarization of hydrogen nuclei can elicit a biological effect (see Belova et al. 2007).

Endpoint

efflux of Ca²⁺ through ion channel proteins

Exposure

- 0–60 Hz
- DC
- 50/60 Hz
- magnetic field
- static magnetic field
- low frequency

Exposure	Parameters
Exposure 1: 0–60 Hz Exposure duration: continuous for 30 min	magnetic flux density: 26 µT (vertical static magnetic field) magnetic flux density: 6.3 µT maximum (AC field 0.7, 1.3, 2.1, 2.5, 3.9, 5.4, 6.3 µT)

Exposure 1

Main characteristics

Frequency	0–60 Hz
Type	magnetic field
Exposure duration	continuous for 30 min
Additional info	static magnetic field and AC field applied simultaneously

Exposure setup

Exposure source	Helmholtz coils coil(s)
Setup	exposures for vertical time-varying and static magnetic field were performed in a two-dimensional coil system; horizontal field generated by three coils consisting of 300 turns of 1 mm copper wire each, spaced 98 mm apart; electric current through the middle coil reduced by 58% to improve the homogeneity of the field; vertical field generated by two Helmholtz coils with a diameter of 346 mm and 740 turns of 1 mm copper wire, spaced 182 mm apart; coil system placed in an underground room, whose walls were build as a Faraday cage; two warm water baths shielded from the MF of the stirring motor and the heating device by a 1 cm thick 200 cm x 170 cm aluminum plate; twelve 1.5 ml tubes exposed simultaneously in a water bath in the exposure device
Sham exposure	A sham exposure was conducted.
Additional info	environmental low frequency field (40-1000 Hz): B=0.09 µT sham exposure done under the environmental static magnetic field of B=16 µT

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	26 µT	-	measured	-	vertical static magnetic field
magnetic flux density	6.3 µT	maximum	measured	-	AC field 0.7, 1.3, 2.1, 2.5, 3.9, 5.4, 6.3 µT

Reference articles

Baureus Koch CL et al. (2003): Interaction between weak low frequency magnetic fields and cell membranes

Exposed system:

organelle/cell part
plasma membrane vesicles preparations from spinach

Methods Endpoint/measurement parameters/methodology

efflux of Ca²⁺ through ion channel proteins (determined via calcium-45-loaded vesicles; scintillation counting)

Investigated system:

organelle/cell part
plasma membrane vesicles preparations

Time of investigation:

before exposure
after exposure

Main outcome of study (acc. to author)

The predictions of the investigated model that at a frequency of 60 Hz the biological effect under investigation would significantly be altered at the amplitudes of 1.3 and 3.9 µT could not be confirmed (i.e. no effects on calcium efflux under exposure).

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Märit and Hans Rausing Charitable Foundation, UK

Foletti A et al. (2010): Calcium ion cyclotron resonance (ICR), 7.0 Hz, 9.2 microT magnetic field exposure initiates differentiation of pituitary corticotrope-derived AtT20 D16V cells
Belova NA et al. (2010): [Lednev's model: theory and experiment]
Liboff AR (2009): Electric Polarization and the Viability of Living Systems: Ion Cyclotron Resonance-Like Interactions
Lisi A et al. (2008): Calcium ion cyclotron resonance (ICR) transfers information to living systems: effects on human epithelial cell differentiation
Belova N et al. (2007): The bioeffects of extremely weak power-frequency alternating magnetic fields
Pazur A et al. (2006): Growth of etiolated barley plants in weak static and 50 Hz electromagnetic fields tuned to calcium ion cyclotron resonance
Comisso N et al. (2006): Dynamics of the ion cyclotron resonance effect on amino acids adsorbed at the interfaces
Baureus Koch CL et al. (2003): Interaction between weak low frequency magnetic fields and cell membranes
Blackman CF et al. (1999): Experimental determination of hydrogen bandwidth for the ion parametric resonance model
Liboff AR (1997): Electric-field ion cyclotron resonance
Trillo MA et al. (1996): Magnetic fields at resonant conditions for the hydrogen ion affect neurite outgrowth in PC-12 cells: a test of the ion parametric resonance model
McLeod BR et al. (1992): Electromagnetic gating in ion channels
Liboff AR et al. (1991): Search for ion-cyclotron resonance in an Na(+)-transport system
Lednev VV (1991): Possible mechanism for the influence of weak magnetic fields on biological systems
McLeod BR et al. (1987): Ion Cyclotron Resonance Frequencies Enhance Ca++-dependent Motility In Diatoms
McLeod BR et al. (1987): Calcium and Potassium cyclotron resonance curves and harmonics in diatoms (A. Coffeaeformis)