MULTIPLE QUANTUM NMR STUDIES OF SODIUM AND POTASSIUM IN THE RAT BRAIN

大鼠脑中钠和钾的多重量子核磁共振研究

• 批准号: 3801926
• 负责人: A C MCLAUGHLIN
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3801926
• 关键词: bioenergetics; brain; brain imaging /visualization /scanning; brain metabolism; cats; ion transport; laboratory rat; liver imaging /visualization /scanning; liver metabolism; membrane permeability; nuclear magnetic resonance spectroscopy; perfusion; potassium channel; quantum chemistry; sodium channel

We previously developed a new approach for studying trans-membrane ion gradients in the intact brain utilizing the different NMR relaxation times of intracellular and extracellular ions. Double quantum NMR spectra are more sensitive than conventional single quantum NMR spectra to changes in relaxation times. Double quantum and single quantum 23Na and 39K NMR spectra were obtained from rat brain in vivo. Upon death, the double quantum 23Na NMR signal increased by a factor of three, while the single quantum signal decreased by 20%. The results are consistent with the well-known influx of sodium ions into the cell, and suggest that double quantum sodium and potassium NMR may be useful in visualizing compromised regions of the brain. We have extended this approach in a number of directions. First we extended the approach to study the cat brain in vivo, and the perfused rat liver. Second, we used double-quantum 23Na NMR to study compartmentation of sodium in the intact brain. Third, we combined multiple-quantum 23Na NMR with 31P NMR to study the correlation between changes in the multiple-quantum sodium NMR signals and changes in cellular energetics. In the last year we performed a comprehensive double quantum 23 Na study of perfused liver using shift reagents. The results indicate that, in this organ, most of the double-quantum signal arises from intracellular sodium ions.

我们以前开发了一种新的方法来研究跨膜 利用不同的NMR弛豫在完整的大脑中的离子梯度 细胞内和细胞外离子的时间。 双量子核磁共振 光谱比常规单量子NMR更灵敏 光谱的弛豫时间的变化。 双量子和单量子 用~（23）Na和~（39）K的量子核磁共振波谱测定了大鼠脑组织的~（23）Na和~（39）K的量子核磁共振波谱。 vivo. 在死亡时，双量子23 Na NMR信号增加了 三倍，而单量子信号下降了20%。 这一结果与众所周知的钠离子内流现象相一致 并表明双量子钠和钾 核磁共振可以用于可视化大脑的受损区域。 我们已将这一做法扩展到若干方面。首先我们 扩展了研究猫脑在体内的方法， 鼠肝 第二，我们用双量子~（23）Na NMR研究了 完整大脑中钠的分隔。 第三，我们结合 多量子~（23）Na NMR和~（31）P NMR研究了相关性 多量子钠NMR信号的变化之间的关系， 细胞能量的变化。 去年，我们进行了全面的双量子23 Na 利用移位试剂进行肝脏灌注的研究。 结果表明， 在这个器官中，大部分双量子信号来自于 胞内钠离子