NMR STUDIES OF CELLULAR METABOLISM

本项目旨在开发和应用活体核磁共振技术 研究代谢及其扰动的光谱方法 化学毒素这些研究的一个主要重点是 开发NMR活性细胞内指示剂分子， 在完整细胞中确定感兴趣的代谢参数。研究 重点关注氟化指标的使用， 核磁共振检测氟的固有灵敏度和必要的 不存在来自未处理细胞的背景氟共振。我们有 先前注意到，在人红细胞悬浮液的NMR研究中， 其中加入了含氟分子， 细胞内和细胞外的化学位移差异 指标利用这种移位差异，研究了 各种分子在细胞内和细胞外空间之间的分布。 随后，我们开始研究氟化的 核苷，利用磁化转移方法， 在稳态条件下快速传输分子的研究。 红细胞经常作为运输研究的模型， 由于其它代谢产物的干扰通常最小， 这可能会使分析复杂化。另外我们有 最近评估了使用全氟三丁胺（FTBA）作为指标， 氧分压的变化。我们正在评估这项技术， 气体压缩玻璃体切除兔眼;这种高精度 这种方法允许氧气流入玻璃体的速率 在真实的时间里被研究。结果发现，玻璃体替代物（FTBA） 作为具有氧的伪一阶半衰期的氧储存器 在完整的眼睛中从FTBA中消除约60分钟。NMR研究 原生动物硕大利什曼原虫代谢多磷酸盐的研究， 导致利什曼原虫病的罪魁祸首也在继续。

This program is aimed at the development and application of in vivo NMR spectroscopic methods for studying metabolism and its perturbation by chemical toxins. A principal focus of these studies has been the development of NMR active, intracellular indicator, molecules to allow determination of metabolic parameters of interest in intact cells. Research has focused on the use of fluorinated indicators as a consequence of the inherent sensitivity of fluorine for NMR detection and the essential absence of background fluorine resonances from untreated cells. We have previously noted that in NMR studies of suspensions of human erythrocytes to which fluorine-containing molecules have been added, there is generally a significant chemical shift difference between intra- and extracellular indicators. Use was made of this shift difference, to study the distribution of various molecules between intra- and extracellular spaces. We have subsequently initiated studies of the transport of fluorinated nucleosides,, making use of magnetization transfer methods which allow the study of rapidly transported molecules under steady state conditions. Erythrocytes have frequently served as models for transport studies since there is generally a minimum of interference due to other metabolic transformations which can complicate the analysis. In addition, we have recently evaluated the use of perfluorotributylamine (FTBA) as an indicator of partial oxygen pressure in vivo. We are evaluating this technique in the gas-compressed vitrectomized rabbit eye; the high precision of this approach has allowed the rate of oxygen flow into the vitreous to be studied in real time. It was found that the vitreous substitute (FTBA) acts as an oxygen reservoir with a pseudo-first order half life of oxygen elimination from FTBA in the intact eye of roughly 60 minutes. NMR studies of the metabolism of polyphosphates by the protozoan Leishmania major, responsible for causing the disease Leishmania, have also continued.