Fujii H, Wan X, Zhong J, Berliner L J, Yoshikawa K
Department of Inflammation Research, Tokyo Metropolitan Institute of Medical Science, Rinshoken, Tokyo, Japan.
Magn Reson Med. 1999 Aug;42(2):235-9. doi: 10.1002/(sici)1522-2594(199908)42:2<235::aid-mrm4>3.0.co;2-y.
This paper reports the first in vivo NMR image of the distribution of NO using the "MRI spin-trapping" technique. NO was complexed with the Fe(II)-chelate spin trap, N-methyl-D-glucamine dithiocarbamate (MGD), verified as (MGD)(2)-Fe(II)-NO by EPR, and the radical distribution was "visualized" by MR images. In rats, the (MGD)(2)-Fe(II)-NO complex was concentrated in the liver displaying significantly enhanced contrast in the vascular structure such as hepatic vein and inferior vena cava. Nitric oxide synthase was verified as the source of NO in rats with septic shock by pre-administration of the competitive inhibitor N-monomethyl-L-arginine, resulting in reduced enhancement. The NO complex was more stable in vivo and a more effective MRI contrast agent than other stable nitrogen containing radicals, such as nitroxides. The MRI spin-trapping method should be a powerful tool for visualizing spatial distributions of free radicals in pathologic organs and tissues when combined with the appropriate radical complexing agent, such as (MGD)(2)-Fe(II) used in these studies. Magn Reson Med 42:235-239, 1999.
本文报道了利用“磁共振成像自旋捕获”技术获得的一氧化氮（NO）分布的首张体内核磁共振图像。NO与铁（II）螯合自旋捕获剂N - 甲基 - D - 葡糖胺二硫代氨基甲酸盐（MGD）络合，经电子顺磁共振（EPR）验证为（MGD）₂ - Fe（II） - NO，其自由基分布通过磁共振图像“可视化”。在大鼠体内，（MGD）₂ - Fe（II） - NO络合物集中在肝脏，在肝静脉和下腔静脉等血管结构中显示出显著增强的对比度。通过预先给予竞争性抑制剂N - 单甲基 - L - 精氨酸，证实一氧化氮合酶是脓毒症休克大鼠体内NO的来源，这导致增强效果减弱。与其他稳定的含氮自由基（如氮氧化物）相比，NO络合物在体内更稳定，是一种更有效的磁共振成像造影剂。当与合适的自由基络合剂（如本研究中使用的（MGD）₂ - Fe（II））结合时，磁共振成像自旋捕获方法应该是一种用于可视化病理器官和组织中自由基空间分布的强大工具。《磁共振医学》42:235 - 239，1999年。
