INFLUENCE OF EMF ON FREE RADICAL MEDIATED TOXOCOLOGICAL PROCESSES

工作总结：尽管流行病学研究表明， 暴露在电磁场(EMF)和 癌症目前几乎没有看似合理的分子机制 解释这一效应。已知的自由基参与了 癌症和其他疾病的病因学增加了电磁场可能 以某种方式通过增加FREE的寿命和/或浓度 激进分子。多年来，在有组织的媒体(例如， 洗涤剂胶束)外加磁场导致平均 能浓缩自由基，延长自由基寿命。 如果这些效应发生在体内，那么这可能解释了一些已报道的 电磁场的生物效应。我们的初步研究主要集中在 完整红细胞作为一种测试系统，可以用来研究 MF对自由基过程的影响。我们发现酮洛芬， 一种光毒性、非类固醇消炎药(结构相关 二苯甲酮)，引起人红细胞完全溶血 只需20分钟的紫外线照射。光溶血作用依赖于 被还原型谷胱甘肽和丁基化抑制 羟基甲苯(BHT)提示其机制与脂质有关 过氧化。当在磁场中进行紫外线照射时 (3500G)50%的细胞发生溶血所需的时间(t+) 显著缩短(78分钟比96分钟)。显著下降 在低至250g的磁场中可以观察到T1/2，但其效应 在100G时消失。我们现在发现，在没有应用程序的情况下 外加磁场，含磁铁矿的聚苯乙烯微球 (Fe3O4)还能显著提高光溶血率。这 对照微球(即不含Fe3O4)或 可溶性铁(FeCl3)的存在这些观察表明 与球体相关的磁场是导致 溶血率增加。我们的发现可以归因于 磁场引起的系统间交叉率的降低 的约化生成的双态三重根对 酮洛芬在红细胞膜上的三重态激发 成分，可能是脂类。据我们所知，这是第一次 MF对毒理学过程(溶血)的影响的演示 众所周知，这是通过自由基机制发生的。

Summary of Work: Although epidemiological studies suggest that there is a weak relationship between exposure to electromagnetic fields (EMF) and cancer there are at present few plausible molecular mechanisms to explain this effect. The known involvement of free radicals in the etiology of cancer and other diseases raises the possibility that EMF may somehow act by increasing the lifetime and/or concentration of free radicals. It has been known for many years that in organized media (e.g. detergent micelles) applied magnetic fields cause an increase in average free radical concentration and lengthen the lifetime of free radicals. If these effects occur in vivo then this may explain some of the reported biological effects of EMF. Our initial studies have focused on the intact erythrocyte as a test system that could be used to study the effects of MF on free radical processes. We have found that ketoprofen, a phototoxic, non-steroidal anti-inflammatory drug (structurally related to benzophenone), caused complete hemolysis of human erythrocytes after only 20 min UV irradiation. Photohemolysis was dependent on the presence of oxygen and was inhibited by reduced glutathione and butylated hydroxytoluene (BHT) suggesting that the mechanism involved lipid peroxidation. When UV irradiation was carried out in a magnetic field (3500G) the time taken for hemolysis to occur in 50% of the cells (t+) was significantly shortened (78 min vs. 96 min). A significant decrease in t1/2 could be observed at fields as low as 250G but the effect disappeared at 100G. We have now found that,in the absence of an applied external magnetic field, polystyrene microspheres containing magnetite (Fe3O4) also dramatically increase the rate of photohemolysis. This effect was not observed when control microspheres (ie no Fe3O4) or soluble iron (FeCl3) were present These observations suggest that the magnetic field associated with the spheres is responsible for the increase in the rate of hemolysis. Our findings can be attributed to a magnetic field induced decrease in the rate of intersystem crossing of the geminate triplet radical pair generated by the reduction of ketoprofen in its triplet excited state by erythrocyte membrane components, probably lipids. To our knowledge these are the first demonstrations of an effect of MF on a toxicological process(hemolysis) that is known to occur via a free radical mechanism.