旋磁场对大鼠实验性缺血心肌保护作用的机制研究

The mechanism of protective effects of rotary magnetic field on expe rimental myocardial ischemia in rats

目的 观察旋磁场对垂体后叶素致心肌缺血的保护作用并探讨其机制。方法 大鼠 3 0只 ,采用静脉注射垂体后叶素 (2U/kg体重 )造成急性心肌缺血动物模型 ,经旋磁场作用后 ,观察心电图ST段升高幅度、T波振幅 ;血清一氧化氮 (NO)含量 ;血清和心肌超氧化物歧化酶 (SOD)活力和脂质过氧化物丙二醛(MDA)含量的变化。结果 40mT旋磁场作用 3 0min ,能减轻垂体后叶素引起的大鼠心肌缺血时血清及心肌SOD的活力降低 (0 .1>P >0 .0 5,P <0 .0 1) ;抑制MDA的生成 (P <0 .0 5) ;增加血清NO含量 ,且在 3 0min时更明显 (P <0 .0 1) ;心电图中ST段升高幅度、T波振幅均较缺血组显著降低 (P <0 .0 5)。结论 在适当场强作用下 ,旋磁场通过增加血清和心肌SOD活力、降低MDA含量 。

Objective To study the effect of ro ta ry magnetic field on experimental myocardial ischemia caused by Pitui trin (Pit) injection in rats. MethodsThirty rats with experimental myocardial ischemia induced by intravenous injection of Pit (2U/kg) were divided into three groups: control group, ischemia g roup, rotary magnetic field group. The ST-segment elevated amplitude, T -wave amplitude of ECG, serum NO content, SOD activity and MAD content in the three groups were observed and compared. Results The 30 mT rotary magentic field for 30 min significantly increa sed SOD activity ( P <0.01) and decreased MDA production ( P <0.0 5) in rats with experimental myocardial ischemia caused by intravenous inje ction of Pit. Meanwhile, the NO content was increased significantly in 30 m in ( P <0.01). The ECG parameters including ST-segment elevation, T- wave amplitude were improved in rotary magnetic field group as compared with those of the ischemic group ( P <0.05). Conclusion The proper intensity of rotary magnetic field has protective effe ct on experimental myocardial ischemia by increasing NO content, SOD ac tivity and decreasing MDA content.