Production and degradation of active oxygen-derived free radicals in oral region : the imaging of free radicals using by the in vivo electron spin resonance (ESR) imaging system.

人们一直认为，自由基在各种疾病的某些方面起着重要作用。这得到了生物系统中产生自由基的间接证据的支持。因此，体内自由基的直接检测对于了解这些疾病的发病机制尤为重要。我们报道了体内电子自旋共振-计算机断层扫描系统的开发，该系统能够在活的小动物身上获得高质量的三维(3D)图像，这种新型的可穿透血脑屏障的氮氧基自旋探针3-methoxycarbonyl-2，2，5，5-tetramethyl-pyrolidine-1-yloxy(MC-PROXYL)。该仪器能够无创地对MC-PROXYL在活体小鼠头部的解剖位置进行三维空间成像。由于MC-PROXYL的氧化还原反应在生物系统中暴露于还原剂中时失去了顺磁性，因此该方法有望成为选择性检测自由基和监测体内疾病动物模型中自由基反应的工具。

It has been thought that free radicals play a significant role in certain aspects of various diseases. This has been supported by indirect evidence of free radical generation in biological systems. Thus direct in vivo detection of free radicals is particularly important in understanding the pathogenesis of these disease. We report the development of in vivo electron spin resonance-computer tomography (ESR-CT) system enabling high-quality three-dimensional (3D) images of a novel blood brain barrier (BBB)-permeable nitroxyl spin probe, 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrolidine-1-yloxy (MC-PROXYL), in living small animals. This instrumentation enabled 3D spatial imaging of anatomical location of MC-PROXYL in headregion of living mice noninvasively. Since the redox reaction of MC-PROXYL losses its paramagnetism when exposed to a reducing agent in biological systems, the methodology employed here could be a promising tool to selectively detect free radicals and to monitor the free radical reactions in animal models of disease in vivo.