Study type: Medical/biological study (experimental study)

Effect of weak electromagnetic field on cardiac work, concentration of thyroid hormones and blood aminotransferase level in the chick embryo. med./bio.

Published in: Acta Vet Hung 2013; 61 (3): 383-392

Aim of study (acc. to author)

To examine the effect of an magnetic alternating field on the heart of chick embryos.

Background/further details

120 fertilized eggs were divided into 4 groups: 1.) control group, developed in a normal incubator, 2.) sham exposure group, incubated in a switched-off magnetic field-generator, 3.) 50 µT-exposure group and 4.) 100 µT-exposure group. After 15, 18 and 20 days of incubation, blood samples were collected by cardiac puncture from the embryos. Cardiac work was determined from the 10th day of incubation. After eclosion, 10 chicks were selected from each group for morphometric measurements of their hearts.
Thyroid hormones play an important role in the regulation of the heart rate and the enzymes alanine aminotransferase and aspartate aminotransferase are indicators of a damaged heart muscle.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous from the first to the last day of incubation (up to 21 days)
Exposure 2: 50 Hz
Exposure duration: continuous from the first to the last day of incubation (up to 21 days)

General information

i) 50 µT ii) 100 µT

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous from the first to the last day of incubation (up to 21 days)
Exposure setup
Exposure source
Chamber eggs were incubated in an incubator with an EMF-generator, 1-18 days of incubation: temperature 37.8 ± 0.1 °C, relative humidity 50-60%, 19-21 days of incubation: temperature 37.2 ± 0.1 °C, relative humidity 60-75%
Setup generator was composed of three parts: a step-down transformer, a adjustable auto transformer and a Helmholtz coil, auto transformer was used for precise selection of the intensity of the magnetic field, Helmholtz coil was wound over a wooden frame (20 cm Π30 cm Π50 cm (width Πheight Πlength)), installed inside the incubator; the axis of the coil and the generated vector of the magnetic field were horizontal
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 50 µT effective value - - ± 5 µT
electric field strength 173 V/m - - - ± 5 V/m

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous from the first to the last day of incubation (up to 21 days)
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT effective value - - ± 10 µT
electric field strength 180 V/m - - - ± 1 V/m

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

No statistically significant differences between the control groups found. From the 17th day of incubation, the heart rate was significantly increased in the exposed groups in comparison to the control groups. Additionally, in the exposed groups, the concentrations of thyroxine and triiodothyronine were significantly increased at incubation day 18 and 20 in comparison to the control groups. Newly-hatched chicks from the 100 µT-exposure group had a significant increased heart weight compared to the control groups and the enzyme activity of aspartate aminotransferase was significantly increased.
The authors conclude that exposure to magnetic alternating fields could have an effect on the physiological function of the heart of chick embryos.

Study character:

Study funded by

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