INFLUENCE OF EMF ON FREE RADICAL MEDIATED TOXOCOLOGICAL PROCESSES

EMF 对自由基介导的毒理学过程的影响

• 批准号: 6106712
• 负责人: COLIN CHIGNELL
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6106712
• 关键词: antiinflammatory agents; butylated hydroxytoluene; cytotoxicity; electromagnetic radiation; erythrocytes; free radicals; glutathione; hemolysis; magnetic field; photochemistry; radiation carcinogenesis; tissue /cell culture; toxicology; triplet state; ultraviolet radiation

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 and lipid peroxidation. 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.

尽管流行病学研究表明， 暴露在电磁场中 (EMF)和癌症的关系，目前几乎没有可信的分子 机制来解释这种影响。已知的自由参与 自由基在癌症和其他疾病的病因提出了 电磁场可能以某种方式通过增加寿命的可能性 和/或自由基的浓度。很多人都知道 在有组织介质（例如洗涤剂胶束）中应用的年份 磁场导致平均自由基增加 浓度和延长自由基的寿命。如果这些 影响发生在体内，那么这可能解释了一些报道的 EMF的生物效应我们最初的研究集中在 完整的红细胞作为一个测试系统，可用于研究 MF对自由基过程的影响。我们发现 酮洛芬，一种具有光毒性的非甾体抗炎药 （结构上与二苯甲酮相关），导致完全溶血 紫外线照射20分钟后的人红细胞。 光溶血依赖于氧的存在， 被还原型谷胱甘肽和二丁基羟基甲苯抑制 (BHT)提示其机制与脂质过氧化有关。 在磁场（3500 G）中进行紫外光照射时， 在50%的细胞中发生溶血所需的时间（T）为 显著缩短（78 min vs. 96 min）。显著降低 在低至250 G的磁场下可以观察到t1/2的变化， 在100 G时消失。我们现在发现，在缺乏 外加磁场，聚苯乙烯微球 含磁铁矿（Fe 3 O 4）也显着增加的速度， 光溶血和脂质过氧化。这种影响不是 当对照微球（即无Fe 3 O 4）或可溶性铁 这些观察结果表明，磁性 与球体相关的场负责增加 溶血率。我们的发现可以归因于磁场 场诱导的系统间穿越率的降低， 通过还原生成的成对三重态自由基对 酮洛芬在红细胞膜上的三重激发态 件.