Tayek J A, Katz J
Department of Internal Medicine, Harbor-University of California, Los Angeles Medical Center, Torrance 90509, USA.
Am J Physiol. 1996 Apr;270(4 Pt 1):E709-17. doi: 10.1152/ajpendo.1996.270.4.E709.
Eight normal controls and nine non-insulin-dependent diabetes mellitus diabetics were, after an overnight fast, infused for 3 h with [6-3H]- and with [U-13C]glucose with six 13C carbons at rates from 0.03 to 0.15 mg.kg-1.min-1. Plasma glucose and lactate were assayed by gas chromatography-mass spectroscopy. Several parameters of glucose metabolism were calculated from the mass isotopomer distribution. Glucose production (GP) determined with [6-3H]- and [U-13C]glucose agreed closely. GP was 1.9 +/- 0.16 (range 1.3-2.5) mg.kg-1.min-1 in controls and 2.8 +/- 0.29 (1.7-4.5) mg.kg-1.min-1 in diabetics (P < 0.05). The correlation in diabetes between plasma glucose and GP (r = 0.911, P < 0.01) was close. Recycling of carbon (8 vs 7%) dilution by unlabeled carbon (2- vs 2.3-fold), and dilution via the tricarboxylic acid cycle (1.5-fold) were similar in controls and diabetics. Gluconeogenesis was 0.90 +/- 0.08 (0.5-1.3) mg.kg-1.min-1 in controls and 1.30 +/- 0.13 (0.8-1.9) mg.kg-1.min-1 in diabetics (P < 0.05). Gluconeogenesis contributions to GP were 46.6 +/- 4.0% (26-61%) in the controls and 48.8 +/- 5.7% (32-83%) in diabetics. We show that, using [U-13C]glucose infusion of 2-5% of glucose turnover (0.03-0.10 mg.kg-1.min-1), a large number of parameters of glucose metabolism may be determined in humans.
8名正常对照者和9名非胰岛素依赖型糖尿病患者在禁食过夜后，以0.03至0.15mg·kg⁻¹·min⁻¹的速率静脉输注[6-³H]-葡萄糖和含6个¹³C碳原子的[U-¹³C]葡萄糖3小时。采用气相色谱-质谱联用仪测定血浆葡萄糖和乳酸。根据质量同位素异构体分布计算了几个葡萄糖代谢参数。用[6-³H]-葡萄糖和[U-¹³C]葡萄糖测定的葡萄糖生成（GP）结果非常接近。对照组的GP为1.9±0.16（范围1.3 - 2.5）mg·kg⁻¹·min⁻¹，糖尿病患者为2.8±0.29（1.7 - 4.5）mg·kg⁻¹·min⁻¹（P<0.05）。糖尿病患者血浆葡萄糖与GP之间的相关性密切（r = 0.911，P<0.01）。对照组和糖尿病患者的碳循环（8%对7%）、未标记碳的稀释（2倍对2.3倍）以及通过三羧酸循环的稀释（1.5倍）相似。对照组的糖异生为0.90±0.08（0.5 - 1.3）mg·kg⁻¹·min⁻¹，糖尿病患者为1.30±0.13（0.8 - 1.9）mg·kg⁻¹·min⁻¹（P<0.05）。糖异生对GP的贡献在对照组中为46.6±4.0%（26 - 61%），在糖尿病患者中为48.8±5.7%（32 - 83%）。我们表明，使用占葡萄糖周转率2 - 5%（0.03 - 0.10mg·kg⁻¹·min⁻¹）的[U-¹³C]葡萄糖输注，可以在人体中测定大量葡萄糖代谢参数。
