Electromagnetic fields of 0.8 mT field strength was applied either alone or with bleomycin throughout the culture period. The frequencies of micronuclei and aneuploidy were analyzed at 28, 88, and 240 h after bleomycin treatment.
Exposure duration: continuous throughout the cultivation period
|continuous throughout the cultivation period
|magnetic flux density
The co-exposure (bleomycin and electromagnetic field) led to a significant increase in the frequencies of micronuclei and aneuploidy compared to the cells treated with bleomycin alone.
However, no difference was found between electromagnetic field exposed and sham exposed control cells.
The frequency of micronuclei induced by bleomycin was increased at 28 h, and persistently increased up to 240 h, but the new levels were not significantly different from the level at 28 h (= no delayed chromosomal instability by electromagnetic fields). Bleomycin alone increased the frequencies of aneuploidy at 28, 88, and 240 h, and significantly higher frequency of aneuploidy was found in the cells analyzed at 240 h compared to the cells examined at 28 h.
The data suggest that the extremely low frequency electromagnetic field enhances the cytotoxicity of bleomycin. Bleomycin might induce delayed chromosomal instability, but no effect of extremely low frequency electromagnetic field was found on the bleomycin-induced delayed chromosomal instability in fibroblast cells.