Study type: Medical/biological study (experimental study)

p53-independent apoptosis in UV-irradiated mouse skin: possible inhibition by 50 Hz magnetic fields. med./bio.

Published in: Radiat Environ Biophys 2002; 41 (2): 155-158

Aim of study (acc. to author)

The effects of exposure of mice to a 50 Hz magnetic field and ultraviolet radiation on apoptosis and associated parameters in the skin should be investigated.

Background/further details

Mice were divided into 4 groups (n=8 each): 1) sham exposure for 24 hours (sham), ultraviolet radiation for 1 hour (UV), exposure to the magnetic field for 24 hours (MF), 2) exposure to the magnetic field for 24 hours, ultraviolet radiation for 1 hour, exposure to the magnetic field for 24 hours, 3) sham exposure for 24 hours, ultraviolet radiation for 1 hour, sham exposure for 24 hours, 4) non-exposed control group.
The delivered UV radiation dose during 1 hour was 400 J/m2.
In the test on p53 protein expression, a known p53-positive skin tumor sample was used as a positive control. A sample processed without the primary antibody was used as a negative control.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: continuous for 24 h (group 1) or 2 times for 24 h (group 2)

General information

ultraviolet radiation was done using lamps that simulated the solar spectrum; mouse dorsal hair was clipped 1 day before ultraviolet radiation

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Exposure duration continuous for 24 h (group 1) or 2 times for 24 h (group 2)
Exposure setup
Exposure source
  • not specified
Sham exposure A sham exposure was conducted.
Additional info during clipping, a magnetic flux density of 5 µT was measured immediately below the clipper; 50 Hz background magnetic field was less than 0.05 µT
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 100 µT - - - -

Reference articles

  • Kumlin T et al. (1998): Effects of 50 Hz magnetic fields on UV-induced skin tumourigenesis in ODC-transgenic and non-transgenic mice.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Apoptosis was increased in all exposure groups (groups 1-3) compared to the control group, with the highest value in in group 3 (sham + UV + sham). Group 1 (sham + UV + MF) showed significantly less apoptosis compared to group 3. Group 2 (MF + UV + MF) also showed a decrease in apoptosis in comparison to group 3 but it was just not significant.
A protein expression of p53 was not detected in any group.
No significant differences in the ornithine decarboxylase enzyme activity were found between the exposure groups.
In the polyamine levels, spermidine and spermine showed a significant decrease in group 2 (MF + UV + MF) compared to group 3 (sham + UV + sham).
The authors conclude that exposure of mice to ultraviolet radiation might induce p53-independent apoptosis in the skin and that exposure to a magnetic field could attenuate this effect.

Study character:

Study funded by

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