Leucine, when ingested with glucose, synergistically stimulates insulin secretion and lowers blood glucose
Leucine, when ingested with glucose, synergistically stimulates insulin secretion and lowers blood glucose
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DOI：
10.1016/j.metabol.2008.09.001
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发表时间：
2008-12-01
影响因子：
9.8
通讯作者：
Nuttall, Frank Q.
中科院分区：
文献类型：
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作者：
Kalogeropoulo, Dionysia;LaFave, Laura;Nuttall, Frank Q.
我们的实验室对摄入蛋白质的代谢影响感兴趣。作为这项研究的一部分，我们目前正在研究摄入的单个氨基酸的代谢影响。当前研究的目的是确定亮氨酸是否刺激胰岛素和/或胰高血糖素分泌，以及当它与葡萄糖一起摄入时是否会改变葡萄糖、胰岛素或胰高血糖素反应。 13 名健康受试者（6 名男性和 7 名女性）在 4 个不同的场合进行了研究。受试者禁食12小时后被送入特殊诊疗室。他们于上午 8:00 收到测试餐。第一次，他们只得到水。此后，他们随机接受25g葡萄糖或1mmol/kg去脂体重亮氨酸或1mmol/kg去脂体重亮氨酸加25g葡萄糖。在摄入测试餐后2.5小时内的不同时间测量血清亮氨酸、葡萄糖、胰岛素、胰高血糖素和α-氨基氮浓度。所提供的亮氨酸含量相当于高蛋白膳食中的亮氨酸含量，即大约 350 克牛排中的亮氨酸含量。摄入亮氨酸后，亮氨酸浓度增加7倍； α-氨基氮浓度增加16%。摄入亮氨酸不影响血清葡萄糖浓度。当亮氨酸与葡萄糖一起摄入时，2.5小时葡萄糖面积反应降低了50%。单独摄入亮氨酸时，会适度增加血清胰岛素面积反应。然而，它使胰岛素面积对葡萄糖的反应额外增加了 66%；也就是说，它几乎使响应增加了一倍。摄入的亮氨酸刺激胰高血糖素的所有增加。摄入的葡萄糖减少了它。当一起摄入时，净效应是胰高血糖素面积基本上没有变化。总之，亮氨酸的剂量相当于高蛋白膳食中的剂量，对油血清葡萄糖或胰岛素浓度几乎没有影响，但确实增加了胰高血糖素浓度。当亮氨酸与葡萄糖一起摄入时，它会减弱血清葡萄糖反应并强烈刺激额外的胰岛素分泌。亮氨酸还可以减弱单独摄入葡萄糖时预期的胰高血糖素减少。数据表明，葡萄糖浓度的升高对于亮氨酸刺激显着的胰岛素分泌是必要的。这反过来又降低了对摄入葡萄糖的葡萄糖反应。由爱思唯尔公司出版
Our laboratory is interested in the metabolic effects of ingested proteins. As part of this research, we currently are investigating the metabolic effects of ingested individual amino acids. The objective of the current study was to determine whether leucine stimulates insulin and/or glucagon secretion and whether, when it is ingested with glucose, it modifies the glucose, insulin, or glucagon response. Thirteen healthy subjects (6 men and 7 women) were studied on 4 different occasions. Subjects were admitted to the special diagnostic and treatment unit after a 12-hour fast. They received test meals at 8:00 AM. On the first occasion, they received water only. Thereafter, they received 25 g glucose or I mmol/kg lean body mass leucine or I mmol/kg lean body mass leucine plus 25 g glucose in random order. Serum leucine, glucose, insulin, glucagon, and a-amino nitrogen concentrations were measured at various times during a 2.5-hour period after ingestion of the test meal. The amount of leucine provided was equivalent to that present in a high-protein meal, that is, that approximately present in a 350-g steak. After leucine ingestion, the leucine concentration increased 7-fold; and the alpha-amino nitrogen concentration increased by 16%. Ingested leucine did not affect the serum glucose concentration. When leucine was ingested with glucose, it reduced the 2.5-hour glucose area response by 50%. Leucine, when ingested alone, increased the serum insulin area response modestly. However, it increased the insulin area response to glucose by an additional 66%; that is, it almost doubled the response. Ingested leucine stimulated all increase in glucagon. Ingested glucose decreased it. When ingested together, the net effect was essentially no change in glucagon area. In summary, leucine at a dose equivalent to that present in a high-protein meal, had little effect oil serum glucose or insulin concentrations but did increase the glucagon concentration. When leucine was ingested with glucose, it attenuated the serum glucose response and strongly stimulated additional insulin secretion. Leucine also attenuated the decrease in glucagon expected when glucose alone is ingested. The data suggest that a rise in glucose concentration is necessary for leucine to stimulate significant insulin secretion. This in turn reduces the glucose response to ingested glucose. Published by Elsevier Inc.