この研究は、マウスに900MHz無線周波（RF）電磁界ばく露（120 μW/cm2、1日4時間、7日間）を与え、その終了から4時間後にブレオマイシン（BLM）を投与して、マウスに適応応答が見られるか否かを検討した。RF単独群、BLM単独群、RF＋BLM群において、i) 白血球のDNA損傷、ii) 血漿、肝と肺の組織での酸化的損傷（MDA:マロンジアルデヒド）と抗酸化状態（SOD:スーパーオキシドジスムターゼ）を調べた。その結果、RF単独群では、BLM単独群とは対照的に、DNA損傷、酸化的損傷は増加しなかった；RF＋BLM群では、BLM誘導性のDNA損傷の低下が見られ、血漿と肝でのMDAレベル低下、肺でのSODレベル上昇が見られた､と報告している。
The detailed summary of this article is not available in your language or incomplete. Would you like to see a complete translation of the summary? Then please contact us →
It should be investigated if exposure of mice to a 900 MHz electromagnetic field induces an adaptive response with higher resistance against bleomycin.
Bleomycin causes damages in cells and tissue comparable to the damage caused by ionizing radiation.
The experiment was divided into two parts: In the first part, DNA damage was examined and in the second part, oxidative stress and the antioxidative status were examined. For the first part, 24 mice and for the second part, 48 mice were divided into 6 groups, respectively (each n=4 and n=8, respectively): 1) cage control, 2) sham exposure, 3) exposure to electromagnetic field only, 4) injection of bleomycin only, 5) sham exposure + bleomycin, 6) exposure + bleomycin. The experiment of the first part was conducted twice.
Bleomycin was administered 4 hours after the last exposure.
|ばく露時間||continuous for 4 h/day for 7 days|
|チャンバの詳細||small plastic boxes|
|ばく露装置の詳細||single restrained mice were kept in small plastic boxes and exposed in an in-house built GTEM cell; the location and orientation of the animals in the GTEM cell during exposure was monitored|
|Sham exposure||A sham exposure was conducted.|
No significant differences could be observed between cage control, sham exposure and exposure to the electromagnetic field alone (groups 1-3) in all experiments.
In mice of groups with bleomycin injection (4-6), a significant increase of DNA damage could be observed 20 minutes after the injection compared to groups 1-3. In consecutive measurements, a progressional decrease of DNA damage with increasing time was observed in groups 4-6, with significant lower DNA damage in the group with exposure to the electromagnetic field (group 6) compared to groups without exposure (groups 4 and 5).
Groups 4-6 showed significantly increased levels of malondialdehyde and significantly decreased levels of superoxide dismutase in all tissues compared to groups 1-3. Additionally, the level of malondialdehyde was significantly lower in plasma and liver and the level of superoxide dismutase significantly higher in the lung in group 6 compared to groups 4 and 5.
The authors conclude that exposure of mice to a 900 MHz electromagnetic field induces an adaptive response with higher resistance against genotoxic or oxidative effects of bleomycin and that this study provides some evidence on the mechanisms of action underlying such an adaption.