Study type: Medical/biological study (experimental study)

Evaluation of rat thyroid gland morphophysiological status after three months exposure to 50 Hz electromagnetic field. med./bio.

Published in: Tissue Cell 2003; 35 (3): 223-231

Aim of study (acc. to author)

To study the effects of an extremely low frequency electromagnetic field on rat thyroid gland.

Background/further details

A total of 89 animals were used. The exposure group consisted of 47 and the control group of 42 animals. To investigate in vivo recovery periode of thyroid gland the animals were divided into four groups differing in the time point of sacrifice after exposure: group 1) sacrificed the day after exposure, group 2) sacrificed one week, group 3) two weeks and group 4) sacrificed three weeks after electromagnetic field exposure.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: repeated daily exposure, 7 h/day, 5 days/week for 3 months

General information

47 animals were exposed, 42 served as control.

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration repeated daily exposure, 7 h/day, 5 days/week for 3 months
Exposure setup
Exposure source
Setup Animals were placed in cages which were placed symmetrically on both sides of the coil.
Additional info Control animals were maintained in a seperate room free of any appliances involved in generation.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 10 V/m - measured - -
magnetic flux density 50 µT minimum unspecified - on the opposite side of the coils
magnetic flux density 500 µT maximum unspecified - at the coils

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Histological analyses showed that the volume density of follicular epithelium and thyroid activation index (ratio of the volume density of follicular epithelium to the volume density of colloid) decreased, while the volume density of colloid and capillary network increased in group 1, 2 and 3. However, the values of all these parameters in group 4 were similar to corresponding control group.
Serum T3 and T4 concentrations were significantly lower in exposed animals of group 2-4 compared to control group.
Results demonstrate that after significant morphophysiological changes caused by extremely low frequency electromagnetic field exposure thyroid gland recovered morphologically, but not physiologically (hormone level), during the investigated recovery period.

Study character:

Study funded by

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