不同波形低频脉冲磁场对大鼠心肌微血管内皮细胞的影响

The effects of low frequency pulsed magnetic fields with different waveforms on cardiac microvascular endothelial cells

目的 研究在固定时间和频率的情况下不同波形的低频脉冲磁场（LF-PMFs）对大鼠心肌微血管内皮细胞（CMECs）增殖、细胞周期、凋亡、迁移、细胞骨架以及一氧化氮（NO）分泌能力的影响.方法 磁场频率为15hz,磁场强度分别为0.6mT、1.2mT、1.8mT、2.4mT,作用时间为4h/d,连续作用5d的情况下,以矩形和三角形2种波形磁场分别作用于离体大鼠心肌微血管内皮细胞,对照组不加干预.结果 矩形波磁场促进内皮细胞增殖（P〈0.01）,使其细胞周期分布发生改变（P〈0.01）,DNA合成期（S期）和合成后期（G2期）细胞比例增加,凋亡率降低（P〈0.05）,细胞迁移能力显著增强（P〈0.01）,曝磁后细胞骨架结构发生重构,应力纤维增多,NO分泌能力增加（P〈0.01）;三角波磁场0.6mT组和2.4mT组促使CMECs增殖（P〈0.05）,细胞周期改变（P〈0.05）,凋亡率降低（P〈0.05）,迁移能力增强（P〈0.05）,细胞骨架重构,NO分泌能力提高（P〈0.05）.而三角波磁场1.2mT组和1.8mT组上述效果均不明显（P〉0.05）.结论 大鼠CMECs的增殖、细胞周期、凋亡、迁移、细胞骨架以及NO分泌能力除受LF-PMFs频率和强度影响外,还受磁场波形的影响.

Objective To investigate the effects of low frequency pulsed magnetic fields （LF-PMFs） on proliferation, the cell cycle, apoptosis, migration, cytoskeleton formation and nitric oxide （NO） secretion in cardiac microvascular endothelial cells （CMECs）. Methods LF-PMFs with rectangular and triangular waveforms at 15 Hz were tested. The CMECs were randomly divided into a control group, 0.6 mT group, 1.2 mT group, 1.8 mT group and 2.4 mT group. Except for the control group, the CMECs were exposed to LF-PMFs 4 h/day for 5 days. Results After 5 days of intervention with rectangular wave LF-PMFs the proliferation of CMECs accelerated and NO secretion was enhanced significantly. The percentages of cells at （ S＋G2 ） phase increased significantly, whereas apoptosis rates were significantly lower than in the control group. The migration of CMECs was facilitated, stress fibers increased and cytoskeleton components were reorganized. After 5 days of intervention with triangular wave LF-PMFs proliferation of CMECs accelerated and NO secretion was significantly enhanced. The percentages of cells at（S＋G2）phase and migration increased, while apoptosis was inhibited. Cytoskeleton components were reorganized after exposure to 0.6 mT and 2.4 mT triangular waveform LF-PMFs. No significant change was detected with 1.2 mT and 1.8 mT triangular waveform LF-PMFs with regard to these variables. Conclusions The effects of LF-PMFs on proliferation, the cell cycle, apoptosis, migration, cytoskeleton formation and NO secretion function of CMECs were infiuenced by the waveform in addition to it＇s intensity and frequency.