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

[超低周波電磁界は酵母及びヒトリンパ球のDNA損傷及び遺伝子発現プロファイルに影響しない] med./bio.

Extremely low-frequency electromagnetic fields do not affect DNA damage and gene expression profiles of yeast and human lymphocytes

著者: Luceri C, De Filippo C, Giovannelli L, Blangiardo M, Cavalieri D, Aglietti F, Pampaloni M, Andreuccetti D, Pieri L, Bambi F, Biggeri A, Dolara P
掲載誌: Radiat Res 2005; 164 (3): 277-285
RISフォーマットで参考文献をダウンロード

この研究は、2つの異なる真核細胞として末梢ヒト血液リンパ球および出芽酵母（Saccharomyces cerevisiae）のDBY747株を用い、超低周波（50 Hz）電磁界（EMF）の影響を調べた。ヘルムホルツコイルシステムを用いて、周波数50 Hz 、磁束密度1、10、または100 μTの磁界ばく露を18時間実施した。EMFばく露の影響評価として、DNA損傷は、リンパ球での単一細胞ゲル電気泳動アッセイ（コメットアッセイ）で評価した。ヒト血液リンパ球および酵母細胞の遺伝子発現プロファイルは、それぞれ13,971および6,212個のオリゴヌクレオチドを含むDNAマイクロアレイで評価した。その結果、EMFばく露群で、対照群に比べ、DAN鎖切断または酸化されたDNA塩基の量の増加は観察されなかった；また、遺伝子発現プロファイルの変化も観察されなかった、と報告している。

研究目的（著者による）

ヒト末梢血リンパ球及び酵母に対する超低周波電磁界の影響を調べること。

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 18 hours

ばく露1

主たる特性
周波数 50 Hz
タイプ
  • electromagnetic field
波形
  • sinusoidal
ばく露時間 continuous for 18 hours
Additional information reference article: D. Andreuccetti, M. Bini, A. Ignesti, R. Olmi, S. Priori and R. Vanni, Helmholtz coils for the generation of standard magnetic fields in biological applications. Proceedings of the VII National Congress of the AIFB, Monte Conero, Ancona (Italy), June 1992. Phys. Med. IX (Suppl. 1), 283-285 (1993).
ばく露装置
ばく露の発生源／構造
ばく露装置の詳細 The HC-50 exposure system consisted of a Helmholtz pair system comprising two parallel, coaxial, circular coils having a diameter of 40.6 cm. The distance between coils was equal to their radius (20.3 cm). Each coil was made up of 16 turns of 0.5-mm-thick enamelled copper wire. The two coils were connected in series so that the same current flowed in both. The field strength was regulated by varying the drive current supplied by an adjustable power unit allowing the HC-50 to produce a 50 Hz magnetic flux density varying from 1 to more than 150 µT.
Additional information Each lymphocyte population was divided into two aliquots. The exposed cell aliquots were incubated at the desired field intensity in a cell incubator containing the HC-50 Helmholtz coil system, and the unexposed cell aliquots were placed in a second incubator used in parallel. As an additional control, some experiments were performed by reversing the current in one of the coils in the HC-50 (sham exposure).
パラメータ
測定量 値 種別 Method Mass 備考
磁束密度 0.1 µT - 測定値 - -
磁束密度 1 µT - 校正 - -
磁束密度 10 µT - 校正 - -
磁束密度 100 µT - 校正 - -
測定および計算の詳細

The actual magnetic flux density is a vector function of the position inside the Helmholtz coil system (being exactly equal to the nominal magnetic flux density in the system center only), but calculations and measurements show that intensity and direction errors with respect to the nominal magnetic flux density are less than 1% in a spherical volume centered in the system center and having a radius equal to one third of the coil radius, i.e. approx, 7 cm in the HC-50. The HC-50 power supply unit was equipped with a solid-state current meter whose LCD was calibrated to indicate the nominal magnetic flux density in microtesla. Scrupulous construction and precise calibration of the current meter guaranteed the overall accuracy, which was within 3% of the 7-cm-radius spherical volume. Although the system accuracy is too high to be assessed with standard magnetic flux density meters (rather the HC-50 itself can be used as a calibration device for such probes), it was checked and confirmed as far as possible with a professional commercial magnetic flux density meter (EMDEX II by Enertech consultants); the same instrument was also used to evaluate the background field intensity in the incubators and in the environment where cell exposure took place.

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）

電磁界ばく露後、対照に対する鎖切断または酸化損傷したDNA塩基の増加、あるいは遺伝子発現プロファイルの変化は認められなかった。このデータは、超低周波電磁界はこれら2つの真核細胞系においてDNA損傷の増加を生じず、遺伝子発現に影響しないことを示唆している。

研究の種別:

研究助成

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