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

摘要

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.%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.