Schmid R, Schusdziarra V, Schulte-Frohlinde E, Maier V, Classen M
Department of Internal Medicine II, Technical University of Munich, West Germany.
J Clin Endocrinol Metab. 1989 Jun;68(6):1106-10. doi: 10.1210/jcem-68-6-1106.
We measured plasma amino acid together with insulin, glucagon, pancreatic polypeptide (PP), and glucose concentrations after the ingestion of a protein meal in lean and obese subjects. The basal plasma amino acid levels were similar in both groups. The postprandial increase in the plasma amino acid levels in the obese subjects was only 15-50% of that in the lean subjects. The mean basal and peak postprandial plasma insulin levels were significantly higher (72 and 165 pmol/L) in the obese group than in the lean group (36 and 115 pmol/L; P less than 0.05-0.01). The postprandial rise in plasma glucagon was largely attenuated in the obese subjects, and there was no difference in plasma PP and glucose levels in the 2 groups. To further evaluate the role of circulating amino acids on pancreatic endocrine function in obese and lean subjects, an amino acid mixture consisting of 15 amino acids was infused iv. During the infusion the plasma amino acid levels were comparable in both groups. Plasma insulin rose by 36 +/- 7 (+/- SE) pmol/L (5 +/- 1 microU/mL) in the lean and 129 +/- 22 pmol/L (18 +/- 3 microU/mL) in the obese subjects, whereas plasma glucagon, PP, and glucose levels were similar in both groups. In view of the 3.6-fold greater insulin responses in the obese subjects, it is likely that circulating amino acids contribute to their hyperinsulinemia in spite of the reduced postprandial rise of amino acids in this group (50-85%). Thus, under physiological conditions amino acids have to be considered as an important regulatory component of postprandial insulin release in obese subjects.
我们测定了消瘦和肥胖受试者摄入蛋白质餐后血浆氨基酸水平以及胰岛素、胰高血糖素、胰多肽（PP）和葡萄糖浓度。两组的基础血浆氨基酸水平相似。肥胖受试者餐后血浆氨基酸水平的升高仅为消瘦受试者的15% - 50%。肥胖组的基础和餐后血浆胰岛素峰值水平（分别为72和165 pmol/L）显著高于消瘦组（分别为36和115 pmol/L；P小于0.05 - 0.01）。肥胖受试者餐后血浆胰高血糖素的升高大幅减弱，两组的血浆PP和葡萄糖水平无差异。为了进一步评估循环氨基酸对肥胖和消瘦受试者胰腺内分泌功能的作用，静脉输注了由15种氨基酸组成的氨基酸混合物。输注期间，两组的血浆氨基酸水平相当。消瘦受试者血浆胰岛素升高36±7（±SE）pmol/L（5±1微单位/毫升），肥胖受试者升高129±22 pmol/L（18±3微单位/毫升），而两组的血浆胰高血糖素、PP和葡萄糖水平相似。鉴于肥胖受试者的胰岛素反应高3.6倍，尽管该组餐后氨基酸升高幅度降低（50% - 85%），循环氨基酸仍可能导致其高胰岛素血症。因此，在生理条件下，氨基酸必须被视为肥胖受试者餐后胰岛素释放的重要调节成分。
