Study type: Medical/biological study (experimental study)

The expression of PHOX2A, PHOX2B and of their target gene dopamine-beta-hydroxylase (DbetaH) is not modified by exposure to extremely-low-frequency electromagnetic field (ELF-EMF) in a human neuronal model. med./bio.

Published in: Toxicol In Vitro 2008; 22 (6): 1489-1495

Aim of study (acc. to editor)

To study the effects of extremely low frequency electromagnetic fields on gene expression and protein expression of PHOX2A, PHOX2B and dopamine-beta-hydroxylase in a human neuroblastoma cell line.

Background/further details

PHOX2A and PHOX2B are essential transcription factors for neuron specification and differentiation. In the central nervous system they are found in all noradrenergic and adrenergic neurons which also express dopamine-beta-hydroxylase (an enzyme that converts dopamine to norepinephrine). Both PHOX2A and PHOX2B are able to activate dopamine-beta-hydroxylase promoter.
The authors tested the hypothesis if extremely low frequency electromagnetic fields could affect the expression of PHOX2A, PHOX2B and dopamine-beta-hydroxylase and thus could lead to a disturbed regulation of the spatial and temporal balance of these factors, probably causing defective development or autonomic dysfunction.
The work is part of the REFLEX project (Risk Evaluation of Potential Environmental Hazards From Low Energy Electromagnetic Field Exposure Using Sensitive in vitro Methods), funded by the European Union.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Modulation type: pulsed
Exposure duration: intermittent, 5 min on - 5 min off, for 16 h
Exposure 2: 50 Hz
Exposure duration: continuous for 16 h
Exposure 3: 50 Hz
Exposure duration: continuous for 48 h

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration intermittent, 5 min on - 5 min off, for 16 h
Modulation
Modulation type pulsed
Rise time 3 s
Fall time 3 s
Additional info

linearly ramped

Exposure setup
Exposure source
  • not specified
  • see reference articles
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2 mT effective value - - -
magnetic flux density 1 mT effective value - - -

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 16 h
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2 mT effective value - - -
magnetic flux density 1 mT effective value - - -

Exposure 3

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 48 h
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT effective value - - -

Reference articles

  • Antonini RA et al. (2006): Extremely low-frequency electromagnetic field (ELF-EMF) does not affect the expression of alpha3, alpha5 and alpha7 nicotinic receptor subunit genes in SH-SY5Y neuroblastoma cell line.
  • Schuderer J et al. (2004): In vitro exposure apparatus for ELF magnetic fields.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

No changes at either transcript or protein level of these important components of the autonomic nervous system and catecholaminergic system were found.

Study character:

Study funded by

Related articles