Study type: Medical/biological study (experimental study)

Stereological analysis of thyroid mast cells in rats after exposure to extremely low frequency electromagnetic field and the following "off" field period. med./bio.

Published in: Acta Biol Hung 2005; 56 (1-2): 43-51

Aim of study (acc. to author)

The influence of extremely low frequency electromagnetic field on thyroid gland mast cells should be investigated on male rats.

Background/further details

Forty-seven animals were exposed from 24 hours after birth. 12 animals each were sacrificed directly (group 1), one week (group 2), two weeks (group 3), and 11 rats three weeks (group 4) after the last day of exposure. The control group consisted of 42 rats.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: 7 h/day, 5 days/week for 3 months starting 24 h after birth

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration 7 h/day, 5 days/week for 3 months starting 24 h after birth
Exposure setup
Exposure source
Setup coil consisting of 1320 turns of 2.5 mm copper wire wound round a wooden frame; cages placed symmetrically on both sides of the coil
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 10 V/m - measured - -
magnetic flux density 500 µT maximum measured - on the cage side near the coil
magnetic flux density 50 µT minimum measured - on the opposite cage side

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

After three months exposure an increased volume density of degranulated (mediator releasing) mast cells (type C) were found in all exposure groups, except in group 3 (two weeks recovery period after the exposure). The numerical density of type C mast cells was increased as well.The ratio of the numerical density and of the volume density of type B mast cells to type C mast cells was lower in all exposed groups as compared to the control groups. The exception was group 2 (one week recovery period) with similar values of the ratio of the volume density in exposure group compared to control group.
These results implicate the sensitivity of thyroid gland mast cells to power frequency electromagnetic fields.

Study character:

Study funded by

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