Livesey G, Wilson P D, Dainty J R, Brown J C, Faulks R M, Roe M A, Newman T A, Eagles J, Mellon F A, Greenwood R H
Department of Nutrition, Diet, and Health, Institute of Food Research, Norwich NR4 7UA, United Kingdom.
Am J Physiol. 1998 Oct;275(4):E717-28. doi: 10.1152/ajpendo.1998.275.4.E717.
The rates (and extent) of appearance of glucose in arterialized plasma from an oral glucose load and from liver (RaO, RaH) can be estimated in humans using radioisotopes, but estimates vary among laboratories. We investigated the use of stable isotopes and undertook 22 primed intravenous infusions of D-[6,6-2H2]glucose with an oral load including D-[13C6]glucose in healthy humans. The effective glucose pool volume (VS) had a lower limit of 230 ml/kg body weight (cf. 130 ml/kg commonly assumed). This VS in Steele's one-compartment model of glucose kinetics gave a systemic appearance from a 50-g oral glucose load per 70 kg body weight of 96 +/- 3% of that ingested, which compared with a theoretical value of approximately 95%. Mari's two-compartment model gave 100 +/- 3%. The two models gave practically identical RaO and RaH at each point in time and a plateau in the cumulative RaO when absorption was complete. Less than 3% of 13C was recycled to [13C3]glucose, suggesting that recycling errors were practically negligible in this study. Causes of variation among laboratories are identified. We conclude that stable isotopes provide a reliable and safe alternative to radioactive isotopes in these studies.
通过口服葡萄糖负荷以及肝脏产生的葡萄糖在动脉化血浆中的出现率（及程度）（RaO、RaH），可在人体中使用放射性同位素进行估算，但不同实验室的估算结果存在差异。我们研究了稳定同位素的应用，并对22名健康人体进行了静脉注射D-[6,6-²H₂]葡萄糖的预充式输注，口服负荷包括D-[¹³C₆]葡萄糖。有效葡萄糖池体积（VS）的下限为230毫升/千克体重（相比之下，通常假定为130毫升/千克）。在Steele的葡萄糖动力学单室模型中，该VS得出，每70千克体重口服50克葡萄糖负荷时，全身葡萄糖出现率为摄入葡萄糖的96±3%，与理论值约95%相近。Mari的双室模型得出的结果为100±3%。这两个模型在每个时间点得出的RaO和RaH实际上相同，且在吸收完成时累积RaO达到平稳状态。¹³C中不到3%会再循环生成[¹³C₃]葡萄糖，这表明在本研究中再循环误差实际上可忽略不计。我们确定了不同实验室结果存在差异的原因。我们得出结论，在这些研究中，稳定同位素为放射性同位素提供了一种可靠且安全的替代方法。
