Yamaguchi Sachiko, Ogiue-Ikeda Mari, Sekino Masaki, Ueno Shoogo
Department of Biomedical Engineering, Graduate School of Medicine, University of Tokyo, Japan.
Bioelectromagnetics. 2006 Jan;27(1):64-72. doi: 10.1002/bem.20177.
We investigated the effects of pulsed magnetic stimulation on tumor development processes and immune functions in mice. A circular coil (inner diameter = 15 mm, outer diameter = 75 mm) was used in the experiments. Stimulus conditions were pulse width = 238 micros, peak magnetic field = 0.25 T (at the center of the coil), frequency = 25 pulses/s, 1,000 pulses/sample/day and magnetically induced eddy currents in mice = 0.79-1.54 A/m(2). In an animal study, B16-BL6 melanoma model mice were exposed to the pulsed magnetic stimulation for 16 days from the day of injection of cancer cells. A tumor growth study revealed a significant tumor weight decrease in the stimulated group (54% of the sham group). In a cellular study, B16-BL6 cells were also exposed to the magnetic field (1,000 pulses/sample, and eddy currents at the bottom of the dish = 2.36-2.90 A/m(2)); however, the magnetically induced eddy currents had no effect on cell viabilities. Cytokine production in mouse spleens was measured to analyze the immunomodulatory effect after the pulsed magnetic stimulation. tumor necrosis factor (TNF-alpha) production in mouse spleens was significantly activated after the exposure of the stimulus condition described above. These results showed the first evidence of the anti-tumor effect and immunomodulatory effects brought about by the application of repetitive magnetic stimulation and also suggested the possible relationship between anti-tumor effects and the increase of TNF-alpha levels caused by pulsed magnetic stimulation.
我们研究了脉冲磁刺激对小鼠肿瘤发展过程和免疫功能的影响。实验中使用了一个圆形线圈（内径 = 15 毫米，外径 = 75 毫米）。刺激条件为脉冲宽度 = 238 微秒，峰值磁场 = 0.25 特斯拉（在线圈中心），频率 = 25 脉冲/秒，1000 脉冲/样本/天，小鼠体内磁诱导涡流 = 0.79 - 1.54 安/米²。在一项动物研究中，B16 - BL6 黑色素瘤模型小鼠从注射癌细胞之日起接受脉冲磁刺激 16 天。肿瘤生长研究显示，刺激组的肿瘤重量显著降低（为假手术组的 54%）。在细胞研究中，B16 - BL6 细胞也暴露于磁场（1000 脉冲/样本，培养皿底部的涡流 = 2.36 - 2.90 安/米²）；然而，磁诱导涡流对细胞活力没有影响。通过测量小鼠脾脏中的细胞因子产生来分析脉冲磁刺激后的免疫调节作用。在上述刺激条件暴露后，小鼠脾脏中肿瘤坏死因子（TNF -α）的产生被显著激活。这些结果首次证明了重复磁刺激所带来的抗肿瘤作用和免疫调节作用，也提示了抗肿瘤作用与脉冲磁刺激引起的 TNF -α水平升高之间可能存在的关系。
