Regulation of reactive oxygen species induced by heavy-ion (carbon) beam; Pursuing the sophistication of heavy-ion cancer therapy

用电子顺磁共振(EPR)自旋捕获法测量了辐射诱导的羟基自由基密度。用EPR自旋探针法可以测量超氧阴离子。过氧化氢也可用EPR自旋探针法测定。这些测量的结果给出了一个预测，即高LET辐射产生的非常密集的羟基自由基不能受到生物可用抗氧化剂浓度的调节。其他活性氧物种，包括低密度羟基自由基，可能被抗氧化剂调节或部分调节。本实验测试了坦普尔对碳离子束辐射致小鼠腿部肌肉纤维化的抑制作用。坦普尔给药剂量对纤维化的影响与预期相反。

Density of radiation induced hydroxyl radical could be measured by electron paramagnetic resonance (EPR) spin trapping method. Superoxide could be measured by EPR spin probing method. Hydrogen peroxide could also be measured by EPR spin probing method. Results from those measurements gave a prediction that the very dense hydroxyl radical generation by high LET radiation can not be regulated by biologically available antioxidants concentration. Other reactive oxygen species including low density hydroxyl radical could possibly be regulated or partly regulated using antioxidants.Inhibitory effect of TEMPOL to the radiation induced fibrosis caused by carbon-ion beam on mouse leg muscle was tested. Administration of TEMPOL dose affect to the fibrosis contrary to expectations.