報告書番号

U96031

タイトル（和文）

磁界曝露が細胞内カルシウムの変動に与える影響

タイトル（英文）

Effect of magnetic field exposure on intracellular calcium mobilization

概要 （図表や脚注は「報告書全文」に掲載しております）

商用周波磁界の曝露が，細胞の情報伝達に関与する細胞内カルシウムを変化させるという研究がある。一方で，磁界の影響はないとする研究もあり，影響の有無は明確ではない。本研究は，磁界曝露による細胞内カルシウムの変動の有無を解明する目的で，ラット胸腺細胞などに５０－Ｈｚ，０．１ｍＴの垂直，水平，回転磁界，および５ｍＴの垂直磁界を３０分ないし４０分間曝露した。細胞内カルシウムの測定には，従来の放射性同位元素ではなく，より精密なリアルタイム測定が可能なフローサイトメーターを用いた。実験の結果，いずれの曝露条件下でも細胞内カルシウムの変化は認められなかった。ラット脾臓細胞や免疫学的に弱く刺激した細胞における曝露実験も行ったが，細胞内カルシウムに変化はなかった。いずれの実験でも曝露後に細胞を試薬で刺激し，使用した細胞が正常であったことを確認した。研究の結果，本実験条件下では磁界による細胞内カルシウムの変化は認められなかった。

概要 （英文）

There have been several studies suggesting the intracellular calcium ([Ca2+]i) mobilization in the cells exposed to power frequency, magnetic fields (MFs). However, the reproducibility is questionable because some other studies contradictorily indicated that no such an effect existed. Objective of the present study is to clarify whether or not the [Ca2+]i mobilization occurs by the MF exposure. We exposed specific-pathogen-free, Sprague-Dawley rat thymocytes to 50-Hz, horizontal, vertical or circularly polarized field at 0.1 mT for 30 min. Facility maximum of 5 mT, vertical MF was also applied to the cells. Flow cytometric analysis was employed to measure the [Ca2+]i in real-time manner because it was much precise than radioisotope method. Obtained results indicate no [Ca2+]i mobilization under the exposure conditions described above. Rat splenocytes or immunologically, suboptimally activated thymocytes were also exposed to the fields. In all these cells no changes in the [Ca2+]i by the MF exposures were evident. In each experiment, a calcium ionophore was added to the cell culture media following an MF exposure as a positive control. By doing that, we assured that the cells were indeed capable of mobilizing [Ca2+]i and the experimental system should have been able to detect the change during the course of MF exposure, if it had occurred. These data together suggest that there is no effect on the [Ca2+]i by the MF exposures under all experimental conditions we have tested.

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