Study type: Medical/biological study (experimental study)

Fifty hertz magnetic fields individually affect chromatin conformation in human lymphocytes: Dependence on amplitude, temperature, and initial chromatin state med./bio.

By: Sarimov R, Alipov ED, Belyaev IY
Published in: Bioelectromagnetics 2011; 32 (7): 570-579
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Aim of study (acc. to author)

To study the effects of 50 Hz magnetic fields on chromatin conformation in human lymphocytes.

Background/further details

Lymphocytes were obtained from two healthy male donors (aged 40 and 23 years).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 15 min - 180 min

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 15 min - 180 min
Additional info for exposure a DC field and the AC field were applied simultaneously
Exposure setup
Exposure source
Setup two pairs of Helmholtz coils, one vertical, one horizontal; horizontal pair: radius of 0.09 m and 1000 turns, connected to an AC generator vertical pair: radius of 0.068 m and 100 turns, connected to a DC power supply and used to zero the ambient magnetic field; DC field parallel to the AC magnetic field; magnetic field in the exposure area homogenous within +/- 5 %
Sham exposure A sham exposure was conducted.
Additional info during sham exposure only the AC field was switched off in the middle of each experiment control samples were incubated at the location with the same DC magnetic field as in exposure/sham exposure
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 43 µT - measured and calculated - +/- 1 µT for the DC field
magnetic flux density 20 µT peak value measured and calculated - 5 µT - 20 µT for the AC field
Additional parameter details

the DC field was only applied to neutralize the geomagnetic field

Reference articles

  • Sarimov R et al. (2005): Exposure to ELF magnetic field tuned to Zn inhibits growth of cancer cells
  • Olsson G et al. (2001): ELF magnetic field affects proliferation of SPD8/V79 Chinese hamster cells but does not interact with intrachromosomal recombination
  • Alipov YD et al. (1996): Difference in frequency spectrum of extremely-low-frequency effects on the genome conformational state of AB 1157 and EMG2 E. coli cells

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The magnetic field exposures (5-20 µT) affected the chromatin conformation. These magnetic field effects differed significantly between the two donors and depended on magnetic flux density and initial condensation of chromatin. While the initial state of chromatin was rather stable in one donor (during different measurements), the initial condensation varied significantly in cells from another donor. Both this variation and the magnetic field effect depended on room temperature during exposure. Despite these variations, the general rule was that magnetic field exposure condensed the initially relaxed chromatin and relaxed the chromatin in cells with initially condensed chromatin. In other words, the initial chromatin state might determine both direction (condensation versus relaxation) and magnitude of the effects.
In conclusion, the data showed that individual effects of 50 Hz magnetic field exposure (5-20 µT) may be observed in human lymphocytes in dependence on the initial state of chromatin and temperature.

Study character:

Study funded by

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