報告書番号

U00008

タイトル（和文）

商用周波磁界と免疫系（その５） --1.4～14 mTrms回転円、及び1～10 mTrms垂直磁界曝露がマクロファージの貪食能に及ぼす影響--

タイトル（英文）

Power frequency magnetic fields and immunologic system. Part V.-Effects of 1.4 to 14 mTrms circularly or 1 to 10 mTrms vertically polarized magnetic field exposures on macrophage phagocytosis.-

概要 （図表や脚注は「報告書全文」に掲載しております）

研究目的は、マウスマクロファージの貪食能が商用周波磁界の曝露により変化するか否かを解明することである。まず曝露時間と被貪食物質であるビーズ濃度を変化させた条件下で14 mT回転円磁界曝露を行った。次に曝露時間・ビーズ濃度を一定とし、回転円磁界（1.4, 7, 14 mT）、及び垂直磁界（1, 5, 10 mT）曝露の影響を、測定細胞数を増やし定量性を高めるためフローサイトメトリー法で調べた。いずれも同時に実験した曝露群と対照群間でそれぞれの測定値を統計学的に比較した。その結果、いずれの条件下でも貪食カーブは曝露により変化しなかった。一部の条件下では貪食率、貪食度に変化が認められたが、変化の増減は一貫しておらず再現性もなかった。曝露時間、ビーズ濃度、磁界特性や強度に依存した反応は認められなかった。本実験条件下では、マクロファージ貪食能に関して磁界曝露の影響はないことが示唆された。

概要 （英文）

Macrophages, which play essential roles in nonspecific host defense system, engulf bacteria and external aggressions by phagocytosis. The measurement of phagocytic activity is applicable to the immunotoxicological evaluations. There has been an increasing number of studies about the MF effects on cellular functions. However, there has been no consensus yet as regards whether or not the MF exposure affects phagocytic activities of macrophage. Objective of this study is to investigate the effects of MF exposures on phagocytosis of murine peritoneal macrophage in vitro under different experimental conditions, such as exposure time and beads concentrations, field characteristics, and exposure doses. The experimental design was as follows: proteose peptone-elicited, peritoneal macrophages were collected from SPF male BALB/c mice. Cells were cultured with DMEM containing 10% FBS. After preincubation at 37℃ in 5% CO2, the media were changed to fresh ones containing latex beads. Cells were then exposed to 50 Hz, 1.4, 7, or 14 mTrms circularly, or 1, 5, or 10 mTrms linearly polarized (vertical) MF for 1 or 2 hours (n=3 to 5). Sham-exposure was conducted simultaneously with an identical exposure system that was not energized. Number of internalized beads per cell was determined with microscopic observation or flow cytometry. The three indices of phagocytosis, i.e., phagocytic curve, percentage of phagocytic cells (PP), and phagocytic index (PI), were used. Statistical comparison was always performed between exposed group and corresponding sham-exposed group. In each experiment, three replications were made. Experiments were carried out in a blind fashion. In phagocytic curves, no appreciable changes were observed in MF-exposed group in comparison with sham group. There was also no statistically significant alteration at any MF exposures in replications. Occasionally observed significant changes in PP and PI were not replicable, and magnitudes of the changes were not manifest. These results indicated that MF exposures did not affect these phagocytic indices under the experimental conditions tested. Obtained data suggested that the phagocytosis of murine peritoneal macrophage was unaffected by exposures of both circularly and vertically polarized MFs at any doses examined.

報告者

キーワード