Schmid R, Schusdziarra V, Schulte-Frohlinde E, Maier V, Classen M
Department of Internal Medicine II, Technical University of Munich, F.R.G.
Pancreas. 1989;4(3):305-14. doi: 10.1097/00006676-198906000-00006.
Protein-rich meals stimulate secretion of insulin, glucagon, and pancreatic polypeptide (PP) from the endocrine pancreas. On the one hand, this is due to increased levels of circulating amino acids, and, on the other, neural and/or endocrine factors can contribute to activation of islet cell function. The present study was designed to determine, first, pancreatic endocrine function and postprandial amino acid levels after a protein and a protein-carbohydrate meal and second, insulin, glucagon, and PP levels during infusion of amino acid mixtures that imitate the postprandial amino acid pattern. In healthy volunteers the ingestion of a protein-rich meal (300 g tenderloin steak) elicited within 1 h an increase of virtually all amino acids by 20-400 mumol/L above basal values. The infusion of two different amino acid solutions available for use in humans showed that Aminosteril-N-Hepa (AS) was better for the imitation of the so-called "insulinogenic" amino acids while Aminoplasmal L-10 (AP) gave more comparable plasma levels of the "glucagonogenic" amino acids. Both solutions were not able to imitate the postprandial amino acid pattern completely. With regard to insulin levels, both solutions gave a comparable increase, while AP but not AS stimulated glucagon and PP levels. This suggests that circulating amino acids may be responsible for 60% of the postprandial insulin response after a protein meal, while their contribution to glucagon release can only be roughly estimated at 30-60%. The contribution of circulating nutrients to the greater insulin response after the protein-carbohydrate meal was comparable (60%), while the attenuated glucagon response can be ascribed almost completely to the effect of circulating nutrients. In conclusion, the present data demonstrate that the composition of amino acid mixtures is as yet not ideal for a complete imitation of the postprandial amino acid pattern. The insulin, glucagon, and PP response depends on the amino acid mixtures and accordingly the respective plasma amino acid concentrations obtained during infusion studies. The adequate imitation of plasma amino acid levels is of critical importance for the evaluation of absorbed and circulating amino acid effects in the postprandial state.
富含蛋白质的餐食会刺激内分泌胰腺分泌胰岛素、胰高血糖素和胰多肽（PP）。一方面，这是由于循环氨基酸水平升高，另一方面，神经和/或内分泌因素可促使胰岛细胞功能激活。本研究旨在首先确定蛋白质餐和蛋白质 - 碳水化合物餐后的胰腺内分泌功能及餐后氨基酸水平，其次确定在输注模仿餐后氨基酸模式的氨基酸混合物期间的胰岛素、胰高血糖素和PP水平。在健康志愿者中，摄入富含蛋白质的餐食（300克里脊肉牛排）在1小时内使几乎所有氨基酸水平比基础值升高20 - 400μmol/L。输注两种可供人类使用的不同氨基酸溶液表明，Aminosteril - N - Hepa（AS）更适合模仿所谓的“促胰岛素”氨基酸，而Aminoplasmal L - 10（AP）能使“促胰高血糖素”氨基酸的血浆水平更接近实际情况。两种溶液都不能完全模仿餐后氨基酸模式。关于胰岛素水平，两种溶液引起的升高相当，而AP能刺激胰高血糖素和PP水平升高，AS则不能。这表明循环氨基酸可能占蛋白质餐后餐后胰岛素反应的60%，而它们对胰高血糖素释放的贡献只能大致估计为30 - 60%。循环营养物质对蛋白质 - 碳水化合物餐后更大胰岛素反应的贡献相当（60%），而减弱后的胰高血糖素反应几乎完全归因于循环营养物质的作用。总之，目前的数据表明，氨基酸混合物的组成对于完全模仿餐后氨基酸模式尚不理想。胰岛素、胰高血糖素和PP反应取决于氨基酸混合物以及输注研究期间获得的相应血浆氨基酸浓度。充分模仿血浆氨基酸水平对于评估餐后状态下吸收和循环氨基酸的作用至关重要。
