Omote Y, Nakajima S, Samejima N, Kobayashi S, Nakajima S, Suzaki T
Department of 1st. Surgery, Asahikawa Medical College, Japan.
Hokkaido Igaku Zasshi. 1988 Mar;63(2):240-9.
Influence of magnetic fields on biological systems is not completely clear. Recently, experiments on the effects of weak not heat inducing electromagnetic fields concerning biological systems have been reported. We have investigated the effects of the weak low-frequency pulsing magnetic field (PMF) concerning the respiratory metabolism and transmembrane ion flux of perfused rat livers.
Livers from male Wistar rats were perfused via the portal vein with 95% O2-5% CO2 saturated Krebs-Henseleit Bicarbonate Buffer maintained at 32 degrees C. In 48 hrs fasted rats, lactate was administered in the perfusate as a substrate of gluconeogenesis in case of necessity. PMF generated by the solenoid coil was applied to the perfused livers. For monitoring of respiratory metabolism of the perfused livers, scanning spectrophotometry and NADH fluorometry were applied to the surface of the liver. The effluent was monitored for PO2 and analyzed for glucose, lactate and pyruvate. Ca2+, Mg2+, Na+, K+, Cl- ion from effluent were also analyzed.
By being exposed to a low-frequency PMF, the O2 consumption increased in the perfused livers of the fed rats, but the degree was variable according to the metabolic state of the liver of each rat. In order to bring about a maximum reductive state, ethanol was given to the perfusate. Ethanol caused an increase in NADH and Lactate/Pyruvate ratio and O2 consumption and an inhibition of glucose production. By exposure to PMF the metabolism of perfused liver was shifted to the re-oxidative state. In lactate administered perfused liver of the 48 hrs fasted rats, PMF caused an increase in the livers sensitivity to glucagon. As regards the transmembrane ion fluxes, PMF acted antagonistically to the ethanol effect, especially when we used perfusate with low Ca2+ concentrations. So that an intimate association between PMF and intracellular Ca2+ regulating system was suggested.
磁场对生物系统的影响尚不完全清楚。最近，已有关于弱而非热诱导电磁场对生物系统影响的实验报道。我们研究了弱低频脉冲磁场（PMF）对灌注大鼠肝脏呼吸代谢和跨膜离子通量的影响。
雄性Wistar大鼠的肝脏通过门静脉用维持在32℃的95% O₂ - 5% CO₂饱和的克雷布斯 - 亨泽莱特碳酸氢盐缓冲液进行灌注。在禁食48小时的大鼠中，如有必要，在灌注液中加入乳酸作为糖异生的底物。由螺线管线圈产生的PMF施加于灌注的肝脏。为监测灌注肝脏的呼吸代谢，在肝脏表面应用扫描分光光度法和NADH荧光测定法。监测流出液中的PO₂，并分析其中的葡萄糖、乳酸和丙酮酸。还分析流出液中的Ca²⁺、Mg²⁺、Na⁺、K⁺、Cl⁻离子。
通过暴露于低频PMF，喂食大鼠的灌注肝脏中的O₂消耗量增加，但增加程度因每只大鼠肝脏的代谢状态而异。为了达到最大还原状态，在灌注液中加入乙醇。乙醇导致NADH和乳酸/丙酮酸比值增加、O₂消耗量增加以及葡萄糖生成受到抑制。通过暴露于PMF，灌注肝脏的代谢转变为再氧化状态。在给48小时禁食大鼠的灌注肝脏中加入乳酸的情况下，PMF导致肝脏对胰高血糖素的敏感性增加。关于跨膜离子通量，PMF对乙醇的作用具有拮抗作用，特别是当我们使用低Ca²⁺浓度的灌注液时。因此提示PMF与细胞内Ca²⁺调节系统之间存在密切关联。
