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

我们以前开发了一种研究跨膜离子的新方法。 利用不同的核磁共振弛豫时间在完整大脑中的梯度 胞内和胞外离子。双量子核磁共振波谱是 比传统的单量子核磁共振谱对变化更敏感 放松时间。双量子和单量子~(23)Na和~(39)K核磁共振 在活体大鼠脑内获得光谱。在死后，替身 量子23Na核磁共振信号增加了三倍，而单一的 量子信号减少了20%。结果与实验结果一致。 众所周知，钠离子流入细胞，并表明 量子钠和钾核磁共振可能有助于对受损的 大脑的不同区域。 在过去的一年里，我们在许多方向上推广了这一方法。 首先，我们将该方法扩展到研究猫的活体大脑--大鼠腿 活体内，以及灌流的大鼠肝脏。其次，我们使用了双量子23Na 核磁共振研究钠在完整大脑中的区隔作用。第三，我们 多量子~(23)Na核磁共振与~(31)P核磁共振的联合研究 在多量子钠核磁共振信号的变化和 细胞能量学。

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. In the last year we have extended this approach in a number of directions. First we extended the approach to study the cat brain in vivo, the rat leg 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.