THE P-31 NMR VISIBILITY OF ATP IN PERFUSED-RAT-LIVER REMAINS ABOUT 90-PERCENT, UNAFFECTED BY CHANGES OF METABOLIC STATE
THE P-31 NMR VISIBILITY OF ATP IN PERFUSED-RAT-LIVER REMAINS ABOUT 90-PERCENT, UNAFFECTED BY CHANGES OF METABOLIC STATE
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DOI：
10.1021/bi00148a008
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发表时间：
1992-08-25
期刊：
影响因子：
2.9
通讯作者：
QUISTORFF, B
中科院分区：
文献类型：
--
作者：
MASSON, S;QUISTORFF, B
在各种代谢条件下，包括常氧和低氧灌注、果糖负荷和不同的恒温缺血时间间隔，对自由喂养和禁食24小时的大鼠进行了灌注大鼠肝脏ATP的P-31核磁共振可见性测试。将ATP的P-31核磁共振信号与在核磁共振采集结束时进行的肝活检上的酶促测定的ATP浓度进行比较。在第一个系列实验中，采用H-1核磁共振水信号作为内参，对细胞内ATP的核磁共振进行了绝对定量：在常氧和缺氧灌注期间，核磁共振未检测到一定量的ATP (0.43 +/- 0.19 mM，平均+/- SD)，约占细胞ATP的12%。然而，在P-31核磁共振光谱和生化分析测量的ATP之间存在高度相关性（斜率= 0.96 +/- 0.09;r2 = 0.93）。在第二组实验中，在整个代谢状态范围内，即果糖负荷（1.0-10 mM）和各种常温缺血间隔（2至12分钟），ATP的NMR和分析生化测量之间存在高度显著的相关性，表明ATP的可见性不变。因此，与Murphy等人的研究相反[Murphy， E., et al. (1988) Biochemistry 27,526 -528]，得出的结论是，在37℃时，ATP在灌注的大鼠肝脏中几乎完全可见，在缺血期间也是如此。
The P-31 NMR visibility of ATP of the perfused rat liver was tested over a wide range of metabolic conditions, including normoxic and hypoxic perfusions, fructose loads, and various intervals of normothermic ischemia, for both ad libitum fed and 24-h fasted rats. The P-31 NMR signal of ATP was compared to the concentration of ATP determined by enzymatic assays on liver biopsies performed at the end of NMR acquisition. In a first series of experiments, the NMR resonance of intracellular ATP was quantitated in absolute terms by applying the H-1 NMR water signal as internal reference: during normoxic and hypoxic perfusions, a constant amount of ATP (0.43 +/- 0.19 mM, mean +/- SD), approximately 12% of the cellular ATP, is not detected by NMR. Nevertheless, there is a high correlation (slope = 0.96 +/- 0.09; r2 = 0.93) between the measurements of ATP by P-31 NMR spectroscopy and by biochemical analysis. In a second series of experiments, there was a highly significant correlation between the NMR and analytical biochemical measurements of ATP for whole range of metabolic states, i.e., fructose loads (1.0-10 mM) and various intervals of normothermic ischemia (ranging from 2 to 12 min), indicating unchanged ATP visibility. Thus, as opposed to the studies of Murphy et al. [Murphy, E., et al. (1988) Biochemistry 27, 526-528], it is concluded that ATP at 37-degrees-C remains almost entirely visible in the perfused rat liver, also during ischemia.