Brain DNA damage and 70-kDa heat shock protein expression in CD1 mice exposed to extremely low frequency magnetic fields.
OBJECTIVE
The question of whether exposure to extremely low frequency magnetic fields (ELF-MF), may contribute to cerebral cancer and neurodegeneration is of current interest. In this study we investigated whether exposure to ELF-MF (50 Hz-1 mT) harms cerebral DNA and induces expression of 70-kDa heat shock protein (hsp70).


METHODS
CD1 mice were exposed to a MF (50 Hz-1 mT) for 1 or 7 days (15 h/day) and sacrificed either at the end of exposure or after 24 h. Unexposed and sham-exposed mice were used as controls. Mouse brains were dissected into cerebral cortex-striatum, hippocampus and cerebellum to evaluate primary DNA damage and hsp70 gene expression. Food intake, weight gain, and motor activity were also evaluated.


RESULTS
An increase in primary DNA damage was detected in all cerebral areas of the exposed mice sacrificed at the end of exposure, as compared to controls. DNA damage, as can be evaluated by the comet assay, appeared to be repaired in mice sacrificed 24 h after a 7-day exposure. Neither a short (15 h) nor long (7 days) MF-exposure induced hsp70 expression, metabolic and behavioural changes.


CONCLUSIONS
These results indicate that in vivo ELF-MF induce reversible brain DNA damage while they do not elicit the stress response.
Mariucci
Giuseppina
G
Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy.
Villarini
Milena
M
Moretti
Massimo
M
Taha
Elena
E
Conte
Carmela
C
Minelli
Alba
A
Aristei
Cynthia
C
Ambrosini
Maria Vittoria
MV
D000818:Animals; D001921:Brain / Q000378:metabolism / Q000528:radiation effects*; D020552:Comet Assay; D004249:DNA Damage; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis*; D008280:Magnetics; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000528:radiation effects; D018384:Oxidative Stress
D018840:HSP70 Heat-Shock Proteins