Stallknecht B, Larsen J J, Mikines K J, Simonsen L, Bülow J, Galbo H
Department of Medical Physiology, The Panum Institute, University of Copenhagen, DK-2200 Copenhagen N, Denmark.
Am J Physiol Endocrinol Metab. 2000 Aug;279(2):E376-85. doi: 10.1152/ajpendo.2000.279.2.E376.
Training increases insulin sensitivity of both whole body and muscle in humans. To investigate whether training also increases insulin sensitivity of adipose tissue, we performed a three-step hyperinsulinemic, euglycemic clamp in eight endurance-trained (T) and eight sedentary (S) young men [insulin infusion rates: 10,000 (step I), 20,000 (step II), and 150,000 (step III) microU x min(-1) x m(-2)]. Glucose and glycerol concentrations were measured in arterial blood and also by microdialysis in interstitial fluid in periumbilical, subcutaneous adipose tissue and in quadriceps femoris muscle (glucose only). Adipose tissue blood flow was measured by (133)Xe washout. In the basal state, adipose tissue blood flow tended to be higher in T compared with S subjects, and in both groups blood flow was constant during the clamp. The change from basal in arterial-interstitial glucose concentration difference was increased in T during the clamp but not in S subjects in both adipose tissue and muscle [adipose tissue: step I (n = 8), 0.48 +/- 0.18 mM (T), 0.23 +/- 0.11 mM (S); step II (n = 8), 0.19 +/- 0.09 (T), -0.09 +/- 0.24 (S); step III (n = 5), 0.47 +/- 0.24 (T), 0.06 +/- 0.28 (S); (T: P < 0.001, S: P > 0.05); muscle: step I (n = 4), 1. 40 +/- 0.46 (T), 0.31 +/- 0.21 (S); step II (n = 4), 1.14 +/- 0.54 (T), -0.08 +/- 0.14 (S); step III (n = 4), 1.23 +/- 0.34 (T), 0.24 +/- 0.09 (S); (T: P < 0.01, S: P > 0.05)]. Interstitial glycerol concentration decreased faster in T than in S subjects [half-time: T, 44 +/- 9 min (n = 7); S, 102 +/- 23 min (n = 5); P < 0.05]. In conclusion, training enhances insulin sensitivity of glucose uptake in subcutaneous adipose tissue and in skeletal muscle. Furthermore, interstitial glycerol data suggest that training also increases insulin sensitivity of lipolysis in subcutaneous adipose tissue. Insulin per se does not influence subcutaneous adipose tissue blood flow.
运动训练可提高人体全身及肌肉的胰岛素敏感性。为研究运动训练是否也能提高脂肪组织的胰岛素敏感性，我们对8名耐力训练组（T）和8名久坐组（S）的年轻男性进行了三步高胰岛素-正常血糖钳夹试验[胰岛素输注速率：10,000（第一步）、20,000（第二步）和150,000（第三步）μU·min⁻¹·m⁻²]。测量动脉血中的葡萄糖和甘油浓度，同时通过微透析测量脐周皮下脂肪组织和股四头肌肌肉间质液中的葡萄糖和甘油浓度（仅葡萄糖）。通过¹³³Xe洗脱法测量脂肪组织血流量。在基础状态下，T组受试者的脂肪组织血流量高于S组，且两组在钳夹过程中血流量保持恒定。在钳夹过程中，T组脂肪组织和肌肉中动脉-间质葡萄糖浓度差相对于基础值的变化增加，而S组未增加[脂肪组织：第一步（n = 8），0.48±0.18 mM（T），0.23±0.11 mM（S）；第二步（n = 8），0.19±0.09（T），-0.09±0.24（S）；第三步（n = 5），0.47±0.24（T），0.06±0.28（S）；（T：P < 0.001，S：P > 0.05）；肌肉：第一步（n = 4），1.40±0.46（T），0.31±0.21（S）；第二步（n = 4），1.14±0.54（T），-0.08±0.14（S）；第三步（n = 4），1.23±0.34（T），0.24±0.09（S）；（T：P < 0.01，S：P > 0.05）]。T组间质甘油浓度下降速度比S组快[半衰期：T组，44±9分钟（n = 7）；S组，102±23分钟（n = 5）；P < 0.05]。总之，运动训练可增强皮下脂肪组织和骨骼肌对葡萄糖摄取的胰岛素敏感性。此外，间质甘油数据表明运动训练还可提高皮下脂肪组织脂肪分解的胰岛素敏感性。胰岛素本身不影响皮下脂肪组织血流量。
