Yamaguchi H, Ikehara T, Hosokawa K, Soda A, Shono M, Miyamoto H, Kinouchi Y, Tasaka T
Department of Physiology, School of Medicine, University of Tokushima, Japan.
Jpn J Physiol. 1992;42(6):929-43. doi: 10.2170/jjphysiol.42.929.
The magnetic flux density was varied intermittently from 0.35 to 1.77T and from 0.07 to 1.54 or 1.77T by manual and automatic switchings, respectively, of the power source of an electromagnet. The durations of the "switching-on time" and "-off time" were varied but kept equal. An electric eddy current induced in the culture medium by changes in the magnetic flux density was simulated. When the durations were shorter than 10s, ouabain-sensitive Rb+ influx (active K+ influx) into cultured HeLa cells was significantly inhibited, but the ouabain-insensitive Rb+ influx (passive K+ influx) was not influenced significantly. Inhibition of active Rb+ influx increased with time during exposure for 2 h. Conversely, K+ efflux from the cells was significantly stimulated by the exposure. Microfluorometric examinations of cells loaded with the fluorescent pH indicator 4-heptadecyl-7-hydroxycoumarin (6 microM) and the membrane potential indicator diS-C3-(5) (1 microM) suggested increase in the negative charge on the cell surface during exposure. The observed changes in the K+ (Rb+) fluxes would be related to change in the electric properties of the cell surface caused by exposure to intermittent electromagnetic fields.
通过分别手动和自动切换电磁铁电源，磁通密度分别在0.35至1.77T以及0.07至1.54或1.77T之间间歇性变化。“开启时间”和“关闭时间”的持续时间有所不同，但保持相等。模拟了由磁通密度变化在培养基中感应产生的电涡流。当持续时间短于10秒时，哇巴因敏感的Rb⁺流入（主动K⁺流入）进入培养的HeLa细胞受到显著抑制，但哇巴因不敏感的Rb⁺流入（被动K⁺流入）未受到显著影响。在暴露2小时期间，主动Rb⁺流入的抑制随时间增加。相反，暴露显著刺激了细胞中的K⁺流出。对加载了荧光pH指示剂4 - 十七烷基 - 7 - 羟基香豆素（6微摩尔）和膜电位指示剂二硫代氰基 - 3 - (5)（1微摩尔）的细胞进行显微荧光测定表明，暴露期间细胞表面负电荷增加。观察到的K⁺（Rb⁺）通量变化可能与暴露于间歇性电磁场引起的细胞表面电学性质变化有关。
