Study type: Medical/biological study (experimental study)

Can histological and histomorphometrical changes be induced in rat mandibular condyle following ovariectomy and long-term extremely low frequency magnetic field exposure? med./bio.

Published in: Biotechnol Biotechnol Equip 2012; 26 (2): 2916-2920

Aim of study (acc. to author)

To investigate whether histopathological changes of the mandibular condyle structure occur in ovariectomized rats exposed to extremely low frequency magnetic fields.

Background/further details

Female rats were divided into four groups (n=10 per group): 1.) control group, 2.) ovariectomy, 3.) exposure and 4.) ovariectomy + exposure.



Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 4 h/day during 6 months

General information

rats were divided into the following four groups: i) control ii) ovariectomy (sham exposure) iii) EMF exposure iv) ovariectomy + EMF exposure

Exposure 1

Main characteristics
Frequency 50 Hz
Exposure duration continuous for 4 h/day during 6 months
Exposure setup
Exposure source
Setup two pairs of Helmholtz coils with a diameter of 70 cm and 125 turns of insulated soft copper wire with a diameter of 1.5 mm, coils placed vertically at a distance of 47 cm inside a 130 cm x 65 cm x 80 cm Faraday cage; rats kept in 43 cm x 42 cm x 15 cm methacrylate boxes
Sham exposure A sham exposure was conducted.
Measurand Value Type Method Mass Remarks
magnetic flux density 1.5 mT - measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

In all experimental groups (groups 2-4), some histopathological changes such as irregular appearance in bone marrow cavities were observed, while the structure in the control group appeared normal. In the ovariectomized rats (groups 2 and 4), a loss in bone marrow was determined, while there was an increased amount of bone marrow in the rats exposed to magnetic field alone (group 3). In both magnetic field exposed groups (groups 3 and 4), a disruption and latency in the calcification and ossification was observed. However, no significant differences occurred in the thickness of the condylar cartilage layers between the groups.
The authors conclude that long-term exposure to extremely low frequency magnetic fields and the ovariectomy could induce histopathological changes in the rat's mandibular condyle. However, magnetic field exposure had no influence on the ovariectomy-induced changes.

Study character:

Study funded by

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