Medical/biological study (experimental study)

Effects of 60 Hz electromagnetic field exposure on APP695 transcription levels in differentiating human neuroblastoma cells med./bio.

By: Rao RR, Halper J, Kisaalita WS

Published in: Bioelectrochemistry 2002; 57 (1): 9-15

Aim of study (acc. to author)

To investigate the possibility of an association between the extremely low frequency electromagnetic field exposure and Alzheimer's disease at the cellular level in vitro.

Background/further details

Amyloid precursor protein (APP) was determined in this study as its cleavage leads to beta-amyloid. Beta-amyloid is the main constituent of amyloid plaques in the brains of Alzheimer's disease patients and it is responsible for neurons death.
Additionally, the influence of differentiation age of the investigated cell lines (2, 10, and 16 days) and several magnetic field strengths (50, 100, and 200 µT) were studied.

Endpoint

molecular biosynthesis: amyloid precursor protein (APP695) gene transcription

Exposure

- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 60 Hz Exposure duration: continuous for 4 h	magnetic flux density: 50 µT unspecified magnetic flux density: 100 µT unspecified magnetic flux density: 200 µT unspecified

Exposure 1

Main characteristics

Frequency	60 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 4 h

Exposure setup

Exposure source	Helmholtz coils
Setup	The coils had an inner diameter of 2,75 inches where the 60 mm Petri dishes were placed and an outer diameter 3.25 inches. The vertical distance between the coils was 0.3125 inch. A switch box was used to randomly select exposure, sham exposure and external coil activation. For exposure, sham exposure and external coil activation, the current was switched in same direction, in the opposite direction and supplied to an identical coil located 1 m away from the sample, respectively.

Exposure source

Helmholtz coils

Setup

The coils had an inner diameter of 2,75 inches where the 60 mm Petri dishes were placed and an outer diameter 3.25 inches. The vertical distance between the coils was 0.3125 inch. A switch box was used to randomly select exposure, sham exposure and external coil activation. For exposure, sham exposure and external coil activation, the current was switched in same direction, in the opposite direction and supplied to an identical coil located 1 m away from the sample, respectively.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	50 µT	unspecified	measured	-	-
magnetic flux density	100 µT	unspecified	measured	-	-
magnetic flux density	200 µT	unspecified	measured	-	-

Measurement and calculation details

The magnetic field was measured with a Gauss meter.

Exposed system:

intact cell/cell culture
IMR 32 (human neuroblastoma cells)

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: APP695 gene transcription (gel electrophoresis, RT-PCR, Northern blot)

Investigated system:

DNA/RNA

Time of investigation:

after exposure

Main outcome of study (acc. to author)

No significant differences in APP965 gene transcription were observed in electromagnetic field exposed cells neither in regard to cell differentiation age, nor to the magnetic field exposure at different magnetic field strengths.

Study character:

medical/biological study
experimental study
full/main study
double blind study

Study funded by

University of Georgia Research Foundation (UGARF), USA

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