Burelle Y, Massicotte D, Lussier M, Lavoie C, Hillaire-Marcel C, Péronnet F
Département de Kinésiologie, Université de Montréal, CP 6128 Centre Ville, Montréal H3C 3J7, Canada G9A 5H7.
J Appl Physiol (1985). 2001 May;90(5):1685-90. doi: 10.1152/jappl.2001.90.5.1685.
The respective oxidation of glycerol and glucose (0.36 g/kg each) ingested simultaneously immediately before exercise (120 min at 68 +/- 2% maximal oxygen uptake) was measured in six subjects using (13)C labeling. Indirect respiratory calorimetry corrected for protein and glycerol oxidation was used to evaluate the effect of glucose + glycerol ingestion on the oxidation of glucose and fat. Over the last 80 min of exercise, 10.0 +/- 0.8 g of exogenous glycerol were oxidized (43% of the load), while exogenous glucose oxidation was 21% higher (12.1 +/- 0.7 g or 52% of the load). However, because the energy potential of glycerol is 18% higher than that of glucose (4.57 vs. 3.87 kcal/g), the contribution of both exogenous substrates to the energy yield was similar (4.0-4.1%). Total glucose and fat oxidation were similar in the placebo (144.4 +/- 13.0 and 60.5 +/- 4.2 g, respectively) and the glucose + glycerol (135.2 +/- 12.0 and 59.4 +/- 6.5 g, respectively) trials, whereas endogenous glucose oxidation was significantly lower than in the placebo trial (123.7 +/- 11.7 vs. 144.4 +/- 13.0 g). These results indicate that exogenous glycerol can be oxidized during prolonged exercise, presumably following conversion into glucose in the liver, although direct oxidation in peripheral tissues cannot be ruled out.
在六名受试者中，采用¹³C标记法测定了在运动前（在68±2%最大摄氧量下运动120分钟）即刻同时摄入的甘油和葡萄糖（各0.36克/千克）的各自氧化情况。使用经蛋白质和甘油氧化校正的间接呼吸热量测定法来评估摄入葡萄糖+甘油对葡萄糖和脂肪氧化的影响。在运动的最后80分钟内，10.0±0.8克外源性甘油被氧化（占负荷的43%），而外源性葡萄糖氧化量高出21%（12.1±0.7克或占负荷的52%）。然而，由于甘油的能量潜力比葡萄糖高18%（4.57千卡/克对3.87千卡/克），两种外源性底物对能量产生的贡献相似（4.0 - 4.1%）。在安慰剂试验（分别为144.4±13.0克和60.5±4.2克）和葡萄糖+甘油试验（分别为135.2±12.0克和59.4±6.5克）中，总葡萄糖和脂肪氧化量相似，而内源性葡萄糖氧化量显著低于安慰剂试验（123.7±11.7克对144.4±13.0克）。这些结果表明，外源性甘油在长时间运动期间可以被氧化，推测是在肝脏中转化为葡萄糖后，尽管外周组织中的直接氧化也不能排除。
