Study type: Medical/biological study (experimental study)

Tempol suppresses micronuclei formation in astrocytes of newborn rats exposed to 50-Hz, 10-mT electromagnetic fields under bleomycin administration. med./bio.

Published in: Mutat Res Genet Toxicol Environ Mutagen 2012; 747 (1): 138-141

Aim of study (acc. to author)

To study the mutagenic effects of co-exposure to 50 Hz magnetic fields and bleomycin. Additionally, it was investigated whether the mutagenic effects of magnetic fields were related to reactive oxygen species by using tempol (4-hydroxy-2,2,6,6-tetramethyl piperidine-1-oxyl), a superoxide radical scavenger.

Background/further details

Three-day-old male rats were sham exposed or co-exposed to 50 Hz magnetic fields and bleomycin (5 or 10 mg/kg body weight) in six groups (n=6 rats each): 1) magnetic field exposure, 2) sham exposure, 3) bleomycin (5 mg) + magnetic field co-exposure, 4) bleomycin (5 mg) + sham exposure, 5) bleomycin (10 mg) + magnetic field co-exposure, 6) bleomycin (10 mg) + sham exposure.
Additionally, four groups of rats (n=4 rats each) were treated with tempol: 7) bleomycin (10 mg/kg) + magnetic field exposure + tempol (200 µmol/kg body weight), 8) bleomycin + sham exposure + tempol, 9) bleomycin + magnetic field exposure + physiological saline solution, 10) bleomycin + sham exposure + physiological saline solution.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 72 h

General information

Rats were divided into 10 groups: 1) magnetic field exposure 2) sham exposure 3) bleomycin (5 mg/kg body weight) + magnetic field co-exposure 4) bleomycin (5 mg) + sham exposure 5) bleomycin (10 mg) + magnetic field co-exposure 6) bleomycin (10 mg) + sham exposure 7) bleomycin (10 mg/kg body weight) + magnetic field exposure + tempol (200 µmol/kg body weight) 8) bleomycin + sham exposure + tempol 9) bleomycin + magnetic field exposure + physiological saline solution 10) bleomycin + sham exposure + physiological saline solution

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration continuous for 72 h
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 10 mT - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

The number of micronucleated astrocytes in the "bleomycin (10 mg) + magnetic field exposure group" (group 5) was 1.6 times higher than that in the appropriate sham exposure group (group 6).
The number of micronuclei in astrocytes of group 7 (co-exposure to magnetic field + bleomycin + tempol) was 40% of that in rats administered with the same dose of bleomycin and physiological saline (group 9) and similar to those of the two sham exposure groups (groups 8 and 10).
The data suggest that the mechanism responsible for the elevated frequency of micronuclei in astrocytes of rats co-exposed to bleomycin and magnetic fields is related to reactive oxygen species.

Study character:

Study funded by

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