Free Radical Monitoring of Brain Injury and their Basic Studies

氧自由基在各种急性神经元疾病中起着重要作用。尤其是神经创伤、中风、创伤性脑损伤、心脏骤停后脑缺血等神经急症与氧化应激密切相关。然而，目前体液中自由基的研究受到检测技术困难的严重阻碍。我们建立了一种以5，5-二甲基-L-吡咯啉-N-氧化物(DMPO)为自旋陷阱的体外电子自旋共振(ESR)方法，用于测定人血中的烷氧基(^OR)。我们发现，这种方法可以检测到由活性氧引起的脂质过氧化产生的^OR。从颈内静脉球部的导管采集血样。对照样本也来自健康志愿者。昭和大学医院急救中心所有神经急症患者的烷氧自由基水平均高于对照组。Edaravone是一种新型的合成自由基清除剂，可在急性缺血性卒中中发挥神经保护作用。这种方法有助于在床边立即监测自由基水平，并能够检测氧化应激和脑损伤的严重程度。在未来，我们将研究使用抗氧化剂或抗氧化剂食品来预防和删除。这项研究得到昭和大学伦理委员会的支持。

Oxygen Free radicals have important roles of various acute neuronal conditions. Especially neuroemergency diseases such as neurotrauma, stroke, traumatic brain injury and ischemia after cardiac arrest are strongly related with oxidative stress. However, the study of free radicals in body fluid is currently severely hampered by technical difficulties in their detection. We have developed an ex vivo electron spin resonance (ESR) method, that employs 5,5-dimethyl-l-pyrroline-N-oxide (DMPO) as a spin trap, to measure the alkoxyl radical (^●OR) in human blood. We found that this method can detect ^●OR produced by lipid peroxidation, which is caused by reactive oxygen species. Blood samples were collected from the catheter of the internal jugular bulb. The control samples were also collected from healthy volunteers. Alkoxyl radical level of all patients with neuroemergency deseases, who were admitted to Showa University Hospital Emergency Centre, were elevated in comparison with control. Alkoxyl radical level was shown the condition of patients and was suppressed after administration of Edaravone, a novel synthetic free radical scavenger shown to exert neuroprotective effect in acute ischemic stroke. This method is useful to monitor the free radical level immediately at bedside and it will enable to detect the oxidative stress and the severity of brain damage. In the future we will examine to prevention and the deletion using antioxidant or antioxidative food. This study was supported by ethical committee of Showa University.