INTRACELLULAR SODIUM IN CARDIOMYOCYTES USING NA-23 NUCLEAR-MAGNETIC-RESONANCE
INTRACELLULAR SODIUM IN CARDIOMYOCYTES USING NA-23 NUCLEAR-MAGNETIC-RESONANCE
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DOI：
10.1016/0167-4889(94)90005-1
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发表时间：
1994-03-31
影响因子：
5.1
通讯作者：
OSBAKKEN, M
中科院分区：
文献类型：
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作者：
IVANICS, T;BLUM, H;OSBAKKEN, M
采用Na-23核磁共振法测定超灌注离体大鼠心肌细胞胞内钠含量。在缓冲液中加入移位试剂三聚磷酸镝，以区分来自细胞内和细胞外缓冲液的核磁共振信号。通过对缺血干预引起的钠核磁共振信号变化的测量，实验确定了细胞内钠信号的核磁共振可见性。通过在每次实验开始时将细胞（珠状）添加到缓冲溶液中，并在每次实验结束时用Triton X-100杀死细胞（珠状），确定钠信号的变化来计算细胞内体积。细胞内钠的可见性（相对于细胞外）为0.47 +/- 0.12（平均+/-标准差，n = 12）。细胞内钠的平均浓度为29 +/- 4.5 mM （n = 12）。这个值远远高于一些研究人员使用核磁共振技术和其他使用不同标准方法获得的结果，但那些评估细胞内钠总量的方法（原子吸收光谱和x射线微量分析）除外。我们得出结论，总Na-i比一般报道的要高，使用其他公认的技术，如离子特异性电极，并且Na-23-NMR分析可以用来准确地测定完整细胞中的Na-i。
Intracellular sodium content in superfused isolated rat cardiomyocytes was measured using Na-23 nuclear magnetic resonance. The shift reagent dysprosium tripolyphosphate was added to the buffer to distinguish between NMR signals from the intracellular region and the extracellular buffer. The NMR visibility of the intracellular sodium signal was experimentally determined by measuring the changes induced in the sodium NMR signals by application of ischemia as an intervention. Intracellular volume was accounted for by determining the change in the sodium signal upon adding cells (in beads) to the buffer solution at the beginning of each experiment and by killing the cells (in beads) with Triton X-100 at the end of each experiment. The visibility of intracellular sodium (relative to extracellular) was 0.47 +/- 0.12 (mean +/- S.D., n = 12). The average intracellular sodium concentration using this visibility is 29 +/- 4.5 mM (n = 12). This value is much higher than results obtained by some investigators using NMR techniques and by others using different standard methods, with the exception of those methods which evaluate the total intracellular sodium (atomic absorption spectroscopy and X-ray microanalysis). We conclude that total Na-i is higher than generally reported, using other accepted techniques such as ion-specific electrodes, and that Na-23-NMR analysis can be used to accurately determine Na-i in intact cells.