Study type: Medical/biological study (experimental study)

A histopathological study on alterations in DMBA-induced mammary carcinogenesis in rats with 50 Hz, 100 muT magnetic field exposure med./bio.

By: Baum A, Mevissen M, Kamino K, Mohr U, Loscher W
Published in: Carcinogenesis 1995; 16 (1): 119-125
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Aim of study (acc. to author)

To investigate wheter 50 Hz magnetic field (MF) exposure has any assisting effect on development or growth of DMBA-induced breast tumors in rats.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50–60 Hz
Exposure duration: 24 h/day, 7 days/week for 91 days

General information

Animals were treated in 4 groups: i) application of dimethylbenz[a]anthracene + EMF exposure ii) application of dimethylbenz[a]anthracen, no EMF exposure iii) EMF exposure iv) neither application of dimethylbenz[a]anthracen nor EMF exposure

Exposure 1

Main characteristics
Frequency 50–60 Hz
Type
Waveform
Exposure duration 24 h/day, 7 days/week for 91 days
Exposure setup
Exposure source
Setup four 1.0 m square coils with 11 turns of 1.5 mm² copper wire on the innner coil and 26 turns of this wire on the outer coil
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT - measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

A total of 216 rats were used in this study, divided into four groups: Group A) 99 animals, DMBA treated, MF exposed. Group B) 99 animals, DMBA treated, MF sham-exposed. Group C) 9 animals, non-DMBA-treated, MF exposed. D) 9 animals, non-DMBA-treated, MF-sham-exposed.
The first DMBA (5mg/rat) application occured prior exposure and was followed by three more applications in a weekly interval up to a total doses of 20 mg/rat.
Histopathological examination was carried out after 91 days of exposure/sham-exposure. MF-exposed, DMBA-treated animals exhibits significantly more macroscopically visible mammary tumors than DMBA-treated sham-exposed controls. Tumor size was significantly larger in MF-exposed rats, too. The number of neoplastic and non-neoplasic lesions did not significantly differ between groups. In MF-exposed groups, significantly more animals exhibit malignant mammary tumors. The data demonstrate that long-term 50 Hz MF exposure of DMBA treated femal rats promotes the growth and progression of mammary tumors, while tumor incidence is not effected.

Study character:

Study funded by

Replication studies

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