Study type: Medical/biological study (experimental study)

Catecholamine release from cultured bovine adrenal medullary chromaffin cells in the presence of 60-Hz magnetic fields. med./bio.

Published in: Bioelectrochemistry 2003; 59 (1-2): 57-64

Aim of study (acc. to author)

To investigate the effects of a 60 Hz magnetic field on the catecholamine (norepinephrine and epinephrine) release in cultured bovine adrenal medullary chromaffin cells.

Background/further details

The following groups were examined: 1.) magnetic flux density of 0.01 mT, 2.) magnetic flux density of 0.1 mT, 3.) magnetic flux density of 1 mT, 4.) magnetic flux density of 2 mT and 5.) sham exposure. In every group three subgroups were examined: a) in the absence of drugs, b) with 2 µM Bay K-6844 (calcium channel activator) and c) with 10 µM dimethylphenylpiperazinium (DMPP, causes a secretory response). Additionally, cells were cultivated either in the inner or the outer wells to get different current densities. The cells were 1,6 or 8 days in culture before the exposure. Cells were exposed to a continuous 60 Hz magnetic field or to a pulsed 60 Hz magnetic field. All experiments were performed in triplicate.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: continuous for 15 min
Exposure 2: 60 Hz
Exposure duration: intermittent for 15 min

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Waveform
Polarization
Exposure duration continuous for 15 min
Exposure setup
Exposure source
Chamber double wound, four square coil Merritt system (13.5 x 13.5 x 13 in.) placed within µ-metal enclosures that were in turn positioned within separate incubators; each set of coils had 33 turns in the outer and 14 turns in the inner coils and was supported by a plexiglas stand
Setup dishes containing cells were placed on a free standing acrylic platform positioned between the inner coils; cells were dispensed into either six well cultures plates (35 mm diameter) or into both the inner wells or outer wells of 60 mm culture dishes
Sham exposure A sham exposure was conducted.
Additional info turn ON/OFF transients were eliminated by ramping magnetic fields up and down over a period of 5 sec.; for individual experiments, temperature typically ranged from 28 to 32°C
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 10 µT unspecified measured - -
magnetic flux density 100 µT unspecified measured - -
magnetic flux density 1 mT unspecified measured - -
magnetic flux density 2 mT unspecified measured - -
current density 0.005 A/m² maximum calculated - in the inner wells
current density 0.034 A/m² maximum calculated - in the outer wells

Exposure 2

Main characteristics
Frequency 60 Hz
Type
Waveform
Exposure duration intermittent for 15 min
Additional info 1.) 30 pulses each of 5 s duration, with a 5 sec duration between the pulses (pulse repetition time of 10 s) and 2 s rise and fall time 2.) 90 pulses each of 5 s duration, with a 5 sec duration between the pulses (pulse repetition time of 10 s) and 2 s rise and fall time
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Additional info turn ON/OFF transients were eliminated by ramping magnetic fields up and down over a period of 5 sec.; for individual experiments, temperature typically ranged from 28 to 32°C
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2 mT unspecified measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

No significant differences in the release of either norepinephrine or epinephrine were detected between sham-exposed and exposed cells in either the absence or presence of Bay K-8644 or dimethylphenylpiperazinium. No effect of an exposure to a 60 Hz magnetic field on calcium influx was regarded in comparison to sham exposure. Additionally, no difference was observed between cultivation in the inner and outer wells due to different current densities was found in the examined endpoints. Neither, an effect of the age of the cells on any of the examined parameters was found.
The authors conclude that catecholamine release from chromaffin cells is not sensitive to a 60 Hz magnetic field at the magnetic flux densities in the 0.01-2 mT range.

Study character:

Study funded by

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