Analysis of free radical reactions in diseases model animals using in vivo ESRI

据报道，自由基与糖尿病、高血压、脑血管意外和癌症等多种疾病有关。在这项研究中，我们利用体内ESR/自旋探针技术研究了自由基生成与疾病发生/发展之间的关系。n -二乙基亚硝胺（DEN）处理组中膜透性硝基探针MC-PROXYL的ESR信号衰减率较对照组增强，而DEN处理组中膜透性较差的氨甲酰- proxyl的ESR信号衰减率没有变化，提示DEN处理大鼠肝脏细胞内腔室产生活性氧。OMRI是一种新开发的成像设备，可以获得更高的空间分辨率和更短的测量时间的自由基图像。我们开发了一种分子成像系统，可以同时观察细胞内和细胞外的氧化还原反应，该系统使用了更多的n <14>或n <15>标记的硝基探针。幻影物体含有抗坏血酸包裹的脂质体，具有膜透性自由基，但不具有膜不透性自由基，其OMRI图像强度随时间降低。该系统应用于非甾体抗炎药诱导的胃溃疡和溃疡性结肠炎等实验性疾病模型的体内自由基检测，并获得了疾病发展诱导的细胞内和/或细胞外的增强自由基生成的体内定位。然而，0.015 T OMRI的图像具有较低的时间和空间分辨率。由于其MRI磁场过低，导致解剖信息不准确。因此，本研究开发了0.4 T的样品输运OMRI系统。利用该样品运输工具OMRI Less获得了由直径2.0 mm、壁厚0.35 mm的圆柱形草管和填充硝基自由基溶液的矩形容器组成的幻影的清晰图像

Free radical is reportedly associated with various diseases such as diabetes, hypertension, cerebrovascular accident, and cancer. In this study, we investigated the relationship between free radical generation and the initiation/development of diseases using in vivo ESR/spin probe technique. The ESR signal decay rate of MC-PROXYL, which is a membrane-permeable nitroxyl probe, in N-diethylnitrosoamine (DEN)-treated group is enhanced compared with that in control group, while the ESR signal decay rate of carbamoyl-PROXYL, which is a less membrane-permeable probe, in DEN-treated group is not changed, suggesting that reactive oxygen species is generated at the intracellular compartment of liver in DEN-treated rat.OMRI is a newly developed imaging apparatus, which enables us to get free radical images with higher space resolution and shorter measuring time. We developed the molecular imaging system that is to visualize the redox reactions between in cell and out of cell simultaneously with … More ^<14>N-or ^<15>N-labeled nitroxyl probes. Phantom objects containing ascorbic acid-encapsulated liposomes with membrane-permeable radicals but not membrane-impermeable ones show a time-dependent decrease of the OMRI image intensity. This OMRI system was applied to the in vivo free radical detection of experimental disease models such as NSAIDs-induced gastric ulcer and ulcerative colitis, and in vivo mapping of enhanced radical generation at the intra-cellular compartment and/or the extra-cellular compartment that was induced by the development of disease was obtainedHowever, the images of 0.015 T OMRI have low time and space resolution, resulting in the inaccurate anatomical information because its MRI magnetic field is too low. So, in this study sample transport OMRI system having 0.4 T was developed. The clear image of the phantom, which is composed of cylindrical grass tube (diameter 2.0 mm, wall thickness 0.35 mm) and rectangular container filled with nitroxyl radical solution, was obtained using this sample transport OMRI Less