研究のタイプ: 医学/生物学の研究 (experimental study)

[50Hz磁界が誘導するゲノム不安定性は抗酸化処理で阻止し得ない動的な進化プロセスである] med./bio.

Genomic instability induced by 50Hz magnetic fields is a dynamically evolving process not blocked by antioxidant treatment.

掲載誌: Mutat Res Genet Toxicol Environ Mutagen 2015; 794: 46-51

この研究は、著者の前報(ヒト神経芽細胞腫細胞株SH-SY5Yにおいて、超低周波磁界(ELF-MF)へのばく露8および15日目に小核出現頻度が上昇し、ゲノム不安定が誘導された可能性が示唆されたと報告)を踏まえ、フォローアップを45日目まで延長した実験を行った。SH-SY5Yは、細胞スーパーオキシド産生剤メナジオン(MQ)の共ばく露の有り、無しのそれぞれの条件下で、50Hz、100μTのMFに24時間ばく露した。小核活性酸素種ROS)、脂質過酸化(LPO)を15、30、45日目に測定した。その結果、前報と一貫して、15日目に小核出現頻度が上昇した;30日目でも見られたが45日目には見られなかった;LPOレベルは30、45日目に低下した;前報と同じく、MQ共ばく露はMFの影響に関係しなかった;MFの遅延性の影響におけるROSの役割を調べるため、抗酸化アセチルシステイン(NAC)を磁界ばく露前に投与すると、NACは効果的に細胞ROSレベルを低下させ、ROS に対するMQの作用を抑制したが、MFの作用は阻止されなかった(MFの遅延性の影響にROS上昇は必要ないことが示唆された)、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 →

研究目的(著者による)

The effects of exposure of human neuroblastoma cells to a 50 Hz magnetic field on oxidative stress and DNA damage should be investigated.

詳細情報

The study based on the results of a previous study by the authors (Luukkonen et al. 2014) and should enlarge the data. Menadione is a free radical-producing DNA damaging agent, and the antioxidant N-acetylcysteine were used in the tests to assess the influence of reactive oxygen species.
Cells were divided into the following groups: 1) exposure to the magnetic field, 2) co-exposure to the magnetic field and menadione, 3) co-exposure to the magnetic field and N-acetylcysteine, 4) co-exposure to the magnetic field, menadione and N-acetylcysteine. For each group, a respective control group with the same treatment but without exposure to the magnetic field was used. Cells were investigated 15, 30 and 45 days after exposure.
3 experiments with 2-3 samples per group, respectively, were performed. Positive controls were used.

影響評価項目

ばく露

ばく露 パラメータ
ばく露1: 50 Hz
ばく露時間: continuous for 24 hours

ばく露1

主たる特性
周波数 50 Hz
タイプ
  • magnetic field
ばく露時間 continuous for 24 hours
ばく露装置
ばく露の発生源/構造
チャンバの詳細 cell culture dishes in temperature-controlled cell culture incubator with 5% CO2
ばく露装置の詳細 a horizontal MF was generated by a pair of Helmholtz coils (340 mm Œ 460 mm, 220 mm distance between the coils) inside an incubator; all cell culture dishes were placed at the center of the coil system, where the magnetic field was homogenous
パラメータ
測定量 種別 Method Mass 備考
磁束密度 100 µT - 測定値 - -

Reference articles

  • Luukkonen J et al. (2014): [ヒト神経芽腫細胞SH-SY5Yにおけるゲノム不安定性、酸化プロセス、ミトコンドリア活性の50Hz磁界による誘導]
  • Markkanen A et al. (2008): [50Hz磁界への事前ばく露はメナジオンで誘導したげっ歯類のL929細胞におけるDNA損傷応答を変化させる]

ばく露を受けた生物:

方法 影響評価項目/測定パラメータ/方法

研究対象とした生物試料:
調査の時期:
  • ばく露後

研究の主なアウトカム(著者による)

The DNA damage was significantly elevated in groups exposed to the magnetic field (groups 1-4) compared to the respective control groups after 15 and 30 days, but not after 45 days.
Lipid peroxidation was significantly decreased in MF-exposed groups 1-4 compared to the respective control groups after 30 and 45 days.
The amount of reactive oxygen species was significantly increased in groups 3 and 4, which were exposed to the magnetic field and treated with N-acetylcysteine or menadione and N-acetylcysteine, compared to their respective control groups.
The authors conclude that exposure of human neuroblastoma cells to a 50 Hz magnetic field could induce DNA damage. Consistently with the previous study, this effect did not depend on co-exposure to menadione and was not blocked by simultaneous exposure to the antioxidant N-acetylcysteine, indicating that the increase in reactive oxygen species is no causal mechanism of action.

研究の種別:

研究助成

関連論文