Pou S, Davis P L, Wolf G L, Rosen G M
Department of Pharmaceuticals Sciences, University of Maryland School of Pharmacy, Baltimore 21201, USA.
Free Radic Res. 1995 Oct;23(4):353-64. doi: 10.3109/10715769509065256.
NMR imaging is a well-established technology for obtaining cross-sectional anatomic pictures of organs and tissues. In addition, NMR can provide valuable information about the physiologic state of organs and tissues, especially, as a consequence of cellular injury. With this in mind, NMR in combination with gadolinium-based contrast enhancing agents has been used to assist in the detection of abnormalities to joints as well as to evaluate the status of damage resulting from an injury to this site. We describe the synthesis of a new nitroxide, which is bioresistant to the one-electron reduction mediated by superoxide in the presence of cysteine. This model mimics the reduction of nitroxides by extracellular secretion of superoxide by PMA-stimulated neutrophils. With this nitroxide, we found, in the range from 15 to 17.5 mumoles, enhancement of an NMR image in the knee joint of rabbits. Of interest is the finding that the contrast image remained for at least 90 minutes. These results demonstrate the utility of nitroxides as contrast enhancing agents for NMR imaging of joints.
核磁共振成像（NMR成像）是一种成熟的技术，用于获取器官和组织的横断面解剖图像。此外，核磁共振可以提供有关器官和组织生理状态的有价值信息，特别是由于细胞损伤的结果。考虑到这一点，核磁共振与钆基造影剂联合使用，以协助检测关节异常，并评估该部位损伤造成的损害状况。我们描述了一种新的氮氧化物的合成，该氮氧化物在存在半胱氨酸的情况下对超氧化物介导的单电子还原具有生物抗性。该模型模拟了经佛波酯（PMA）刺激的中性粒细胞细胞外分泌超氧化物对氮氧化物的还原作用。使用这种氮氧化物，我们发现在15至17.5微摩尔的范围内，兔膝关节的核磁共振图像增强。有趣的是，发现对比图像至少持续90分钟。这些结果证明了氮氧化物作为关节核磁共振成像造影剂的效用。
