ABSTRACT

The experimental data support the hypothesis that extremely low frequency magnetic field (ELF-MF) can affect cell membranes. Since our previous studies suggested that MF changes the permeability of cell membrane, in this study we focused on the cell membrane and investigated the effect of 60 Hz, 50 mT MF on the membrane potential and membrane proteins. The membrane potentials of three cultured human cancer cell lines, A549, MES-SA, and MES-SA/Dx5, were increased by exposure to ELF-MF. When exposed to MF and an anticancer drug, changes in the membrane potentials were detected in A549 and MES-SA cells, but not in the multi drug-resistant cells, MES-SA/Dx5. We examined whether MF has an influence on the membrane proteins extracted from cultured A549 cells, using DiBAC₄(3) dye enhanced fluorescence binding to a hydrophobic site. The increase in fluorescence observed following MF exposure for 10 min indicated that the structure of the hydrophobic site on the membrane proteins changed and became more likely to bind the probe dye. A decrease in fluorescence was detected following exposure to MF for 240 min. These results indicated that 60 Hz, 50 mT MF causes changes in the membrane potential of cultured cancer cells and the conformation of membrane proteins extracted from cultured cancer cells, and has different effects depending on the exposure time.

摘要

实验数据支持极低频磁场（ELF-MF）可以影响细胞膜的假设。由于我们之前的研究表明 MF 会改变细胞膜的通透性，因此在本研究中，我们重点研究了细胞膜，并研究了 60 Hz、50 mT MF 对膜电位和膜蛋白的影响。三种培养的人类癌细胞系 A549、MES-SA 和 MES-SA/Dx5 的膜电位因暴露于 ELF-MF 而增加。当暴露于 MF 和抗癌药物时，在 A549 和 MES-SA 细胞中检测到膜电位的变化，但在多重耐药细胞 MES-SA/Dx5 中未检测到。我们使用 DiBAC ₄检查了 MF 是否对从培养的 A549 细胞中提取的膜蛋白有影响(3) 染料增强与疏水位点的荧光结合。MF 暴露 10 分钟后观察到的荧光增加表明膜蛋白上疏水位点的结构发生了变化，变得更有可能与探针染料结合。在暴露于MF 240分钟后检测到荧光降低。这些结果表明，60 Hz、50 mT MF 引起培养癌细胞的膜电位和从培养的癌细胞中提取的膜蛋白构象的变化，并根据暴露时间产生不同的影响。