Harakawa Shinji, Nedachi Takaki, Shinba Toshikazu, Suzuki Hiroshi
Bio-Self-Regulating Science Laboratory, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 0808555, Japan.
Hakuju Institute for Health Science, Tokyo 1510063, Japan.
Biology (Basel). 2022 Feb 17;11(2):323. doi: 10.3390/biology11020323.
In BALB/c mice, immobilization-increased plasma glucocorticoid (GC) levels are suppressed by extremely low frequency (ELF) electric fields (EF). The aim of this study was to advance our understanding of the biological effects of ELF-EF, using its suppressive effect on the GC response. Mice were exposed to a 50 Hz EF of 10 kV/m via a parallel plate electrode and immobilized as needed. We examined the suppressive effect of ELF-EF on GC level change after repeated immobilizations, electrode polarization, and EF shielding of different portions of the mouse body parts. Additionally, bodyweight changes owing to stress and EF were examined. Immobilization-induced reduction in the plasma GC levels was reproduced in mice with stress and EF exposure, regardless of the stress episode numbers and electrode polarization. Furthermore, when the head of mice was shielded from the EF, the suppressive effect was possibly relatively lower than that when the abdomen was shielded. The bodyweight of the mice decreased for 3 days after immobilization before recovering; ELF-EF did not affect the bodyweight. Thus, to elicit the biological effects of the EF, not only the size of the area where the EF is distributed but also the area where the field is distributed should be important. The results also confirmed the stableness of the present experimental system, at least in terms of the stress-reducing effect. In addition, the restriction in this study caused weight loss, but ELF-EF was not considered to affect it. The results improve the understanding of the biological effect and medical applications of ELF-EF.
在BALB/c小鼠中，固定引起的血浆糖皮质激素（GC）水平升高可被极低频（ELF）电场（EF）抑制。本研究的目的是利用ELF-EF对GC反应的抑制作用，加深我们对其生物学效应的理解。小鼠通过平行板电极暴露于10 kV/m的50 Hz EF，并根据需要进行固定。我们研究了ELF-EF对重复固定、电极极化以及小鼠身体不同部位EF屏蔽后GC水平变化的抑制作用。此外，还检测了应激和EF导致的体重变化。无论应激次数和电极极化情况如何，应激和EF暴露的小鼠均重现了固定诱导的血浆GC水平降低。此外，当小鼠头部被EF屏蔽时，抑制作用可能相对低于腹部被屏蔽时。小鼠在固定后体重下降3天，然后恢复；ELF-EF不影响体重。因此，要引发EF的生物学效应，不仅EF分布区域的大小，而且电场分布的区域都应该很重要。结果还证实了本实验系统的稳定性，至少在减轻应激方面。此外，本研究中的限制导致了体重减轻，但ELF-EF被认为不会影响体重。这些结果增进了对ELF-EF生物学效应和医学应用的理解。
