极低频电磁场对大鼠心肌脂质过氧化的影响

目的 研究极低频电磁场（ELF EMFS）对大鼠心肌脂质过氧化的影响。方法 测定了 ELF EMFS暴露前后健康、缺血和铅暴露大鼠心肌的超氧化物歧化酶（SOD）活力及丙二醛（MDA）含量。结果 ELF EMFs未引起大鼠心肌SOD活力和MDA含量明显变化;ELF EMFs导致铅暴露大鼠心肌SOD活力由暴露前（31.24±1.08）μ/mg prot降至（29.20±1.14）U/p prot,P<0.01,MDA含量由（1.24±0.21）nmol/mg prot上升为（1.71±0.63）nmol/mg prot,P<0.01;结扎冠脉造成实验性缺血的心肌组织,经ELF EMFs暴露后,SOD活力由（24.46±2.99）U/mg prot上升至（29.40±3.19）U/mg prot,P<0.01,MDA含量由（1.83±0.59）nmol/mg prot上升为（2＊ 士1.05）nmol/mg prot。结论ELF EMFs和铅具有协同作用,可干扰心肌自由基代谢,加速脂质过氧化,进而对心肌造成损伤;同时ELF EMFS似能缓解缺血心肌的脂质过氧化。

Effects of Extremely Low Frequency Electromagnetic Fields on Lipid Peroxidation of Myocardium in Rats

ve To study the effects of extremely low frequency electromagnetic fields (ELF EMFs) on lipid peroxidation of myocardium in rats. Methods The activities of superoxide dismutase (SOD) and the contents of malonaldehyde (MDA) of the myocardium tissue of rats under the different conditions such as healthy state, my-ocardiac ischemic state and lead-exposure state before and after ELF EMFs exposure were determined respectively. Results ELF EMFs exposure didn't induce significant changes of SOD activities and MDA contents in myocardium of healthy rats, but caused the SOD activities of myocardium of lead-exposure rats to decrease from (31.24?1.08)U/mg prot before exposure to ELF EMFs to (29.20?1.14) U/mg prot after exposure to ELF EMFs (P<0.01), and in-duced the increase of MDA content of myocardium of lead-exposure rats from (1.24?.21)nmol/mg prot before ex-posure to ELF EMFs to (1.71?.63)nmol/mg prot after exposure to ELF EMFs. The SOD activity of ischemic myocardium pretreated by coronary artery ligation increased from (25.46?.99) U/mg prot before exposure to ELF EMFs to (29.40?3.19) U/mg prot after exposure to ELF EMFs (P<0.01) . The MDA contents of ischemic my-ocardium pretreated by coronary artery ligation increased from (1.83 + 0.59) nmol/mg prot before exposure to ELF EMFs to (2.17?1.05)nmol/mg prot after exposure to ELF EMFs. Conclusion The combination of ELF EMFs and lead exposure did damage to the myocardium tissue, probably through interfering the metabolism of free radical and enhancing the lipid peroxidation. On the contrary ELF EMFs could alleviate the lipid peroxidation of ischemic my-ocardium.