Study type: Medical/biological study (experimental study)

Tumor promotion in a breast cancer model by exposure to a weak alternating magnetic field. med./bio.

Published in: Cancer Lett 1993; 71 (1-3): 75-81

Aim of study (acc. to author)

To determine if a weak alternating magnetic field (MF) exposure exerts tumor promoting or co-promoting effects in a rat breast cancer model. The chemical carcinogen DMBA was used to induce mammary tumors.

Background/further details

DMBA (5mg/rat) was given at the onset of exposure and therafter at weekly intervals up to a total does of 20 mg/rat.

Endpoint

Exposure

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

General information

Female rats were divided into two groups of 99 rats and were housed 9 rats per cage.

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration 24 h/d, 7 d/week for 91 days
Exposure setup
Exposure source
Chamber 6 exposure chamber (three for MF exposure and the other three for sham exposure); Acrylic cages/ 390 mm x 550 mm x 220 mm.
Setup Each rat recieved 5 mg of dimethylbenz(a)anthracene dissolved in sesame oil (1ml/rat) and was placed into its home cage into the exposure chamber.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT unspecified measured - -
electric field strength 40 V/m minimum measured - 100 V/m max value.

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Magnetic field exposed rats exhibited statistically significantly more tumors than sham-exposed animals. The tumor size as estimated by palpation was significantly larger in exposed animals 13 weeks after DMBA application. However, the mean number of tumors per tumor-bearing rat did not differ. The results of this study demonstrate that MF exposure in this DMBA rat model promotes the growth and increases the inzidence of mammary tumors.

Study character:

Study funded by

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