Department of Biophysics, Faculty of Medicine, Mersin University, Mersin, Turkey.
Department of Biophysics, Faculty of Medicine, Kahramanmaras Sutcu Imam University, Kahramanmaras, Turkey.
Toxicol Ind Health. 2020 Feb;36(2):119-131. doi: 10.1177/0748233720912061.
The aim of the present study was to systematically investigate the effects of chronic exposure to extremely low-frequency electromagnetic field (ELF-EMF) on electrophysiological, histological and biochemical properties of the diaphragm muscle in rats. Twenty-nine newly weaned (24 days old, 23-80 g) female ( = 15) and male ( = 14) Wistar Albino rats were used in this study. The animals were randomly divided into two groups: the control group and the electromagnetic field (EMF) group. The control group was also randomly divided into two groups: the control female group and the control male group. The EMF exposure group was also randomly divided into two groups: the ELF-EMF female group and the ELF-EMF male group. The rats in the ELF-EMF groups were exposed for 4 h daily for up to 7 months to 50 Hz frequency, 1.5 mT magnetic flux density. Under these experimental conditions, electrophysiological parameters (muscle bioelectrical activity parameters: intracellular action potential and resting membrane potential and muscle mechanical activity parameter: force-frequency relationship), biochemical parameters (Na, K, Cl and Ca levels in the blood serum of rats; Na-K ATP enzyme-specific activities in muscle tissue; and free radical metabolism in both muscle tissue and serum) and transmission electron microscopic morphometric parameters of the diaphragm muscle were determined. We found that chronic exposure to ELF-EMF had no significant effect on the histological structure and mechanical activity of the muscle and on the majority of muscle bioelectrical activity parameters, with the exception of some parameters of muscle bioelectrical activity. However, the changes in some bioelectrical activity parameters were relatively small and unlikely to be clinically relevant.
本研究旨在系统地研究慢性暴露于极低频电磁场 (ELF-EMF) 对大鼠膈神经肌肉的电生理、组织学和生化特性的影响。本研究使用了 29 只刚断奶的（24 天大，23-80 克）雌性（=15）和雄性（=14）Wistar 白化大鼠。这些动物被随机分为两组：对照组和电磁场（EMF）组。对照组又随机分为两组：雌性对照组和雄性对照组。EMF 暴露组也随机分为两组：雌性 ELF-EMF 组和雄性 ELF-EMF 组。ELF-EMF 组的大鼠每天暴露于 50Hz 频率、1.5mT 磁感应强度的电磁场中 4 小时，持续长达 7 个月。在这些实验条件下，测定了膈神经肌肉的电生理参数（肌肉生物电活动参数：细胞内动作电位和静息膜电位；肌肉机械活动参数：力频率关系）、生化参数（大鼠血清中 Na、K、Cl 和 Ca 水平；肌肉组织中 Na-KATP 酶的特异性活性；以及肌肉组织和血清中的自由基代谢）和透射电镜形态计量参数。我们发现，慢性暴露于 ELF-EMF 对肌肉的组织学结构和机械活动以及大多数肌肉生物电活动参数没有显著影响，除了一些肌肉生物电活动参数。然而，一些生物电活动参数的变化相对较小，不太可能具有临床相关性。
