The accumulation of 2-deoxy-D-glucose-6-phosphate (2DG6P), detected using 31P NMR spectroscopy, has been used as a measure of the rate of glucose uptake, yet the accuracy of this measurement has not been verified. In this study, isolated rat hearts were perfused with different substrates or isoproterenol for 30 min before measurement of either 2DG6P accumulation or [2-3H]glucose uptake, without and with insulin. Basal contractile function and metabolite concentrations were the same for all hearts. The basal rates of 2DG6P accumulation differed significantly, depending on the preceding perfusion protocol, and were 38-60% of the [2-3H]glucose uptake rates, whereas insulin-stimulated 2DG6P accumulation was the same or 71% higher than the [2-3H]glucose uptake rates. Therefore the ratio of 2DG6P accumulation/[2-3H]glucose uptake rates varied from 0.38 to 1.71, depending on the prior perfusion conditions or the presence of insulin. The rates of 2DG6P hydrolysis were found to be proportional to the intracellular 2DG6P concentrations, with a K(m) of 17.5mM and V(max) of 1.4 micromol/g dry weight/min. We conclude that the rates of 2DG6P accumulation do not accurately reflect glucose uptake rates under all physiological conditions in the isolated heart and should be used with caution.

中文翻译：

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2-脱氧-D-葡萄糖-6-磷酸的积累作为离体灌注心脏中葡萄糖摄取的量度：31P NMR 研究。

使用 31P NMR 光谱检测到的 2-脱氧-D-葡萄糖-6-磷酸 (2DG6P) 的积累已被用作葡萄糖摄取率的量度，但该测量的准确性尚未得到验证。在这项研究中，在没有和有胰岛素的情况下，在测量 2DG6P 积累或 [2-3H] 葡萄糖摄取之前，用不同的底物或异丙肾上腺素灌注离体大鼠心脏 30 分钟。所有心脏的基础收缩功能和代谢物浓度相同。2DG6P 积累的基础率显着不同，具体取决于先前的灌注方案，是 [2-3H] 葡萄糖摄取率的 38-60%，而胰岛素刺激的 2DG6P 积累与 [2] 相同或高 71% -3H]葡萄糖摄取率。因此，2DG6P 积累/[2-3H] 葡萄糖摄取率的比率从 0 变化。38 到 1.71，取决于先前的灌注条件或胰岛素的存在。发现 2DG6P 水解的速率与细胞内 2DG6P 浓度成正比，K(m) 为 17.5mM，V(max) 为 1.4 微摩尔/克干重/分钟。我们得出结论，2DG6P 积累率不能准确反映离体心脏在所有生理条件下的葡萄糖摄取率，应谨慎使用。