Effect of glutamine on leucine metabolism in humans
Effect of glutamine on leucine metabolism in humans
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DOI：
10.1152/ajpendo.1996.271.4.e748
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发表时间：
1996-10-01
影响因子：
5.1
通讯作者：
Darmaun, D
中科院分区：
文献类型：
--
作者：
Hankard, RG;Haymond, MW;Darmaun, D
本研究的目的是确定谷氨酰胺的假定蛋白合成代谢作用是否1）由蛋白合成增加或蛋白分解减少介导，以及2）是否对谷氨酰胺具有特异性。7名健康成年人在吸收后状态下静脉输注L-[1-C-14]亮氨酸5小时，同时随机接受一天一次的盐水或L-谷氨酰胺（800 μ mol . L-谷氨酰胺）肠内输注。kg（-1）。h（-1），相当于0.11 g N/kg）。使用相同的方案研究了另外7名受试者，但他们接受了甘氨酸的等氮输注。使用血浆α-酮异己酸C-14比活度和呼吸中（CO2）-C-14排泄率测量亮氨酸出现率（R（aLeu））（蛋白质降解指数）、亮氨酸氧化率（Ox（Leu））和非氧化性亮氨酸处置率（NOLD）（蛋白质合成指数）。在谷氨酰胺输注期间，血浆谷氨酰胺浓度加倍（673+/-66对1，184 +/-37 μ M，P
The aim of this study was to determine whether the putative protein anabolic effect of glutamine 1) is mediated by increased protein synthesis or decreased protein breakdown and 2) is specific to glutamine. Seven healthy adults were administered 5-h intravenous infusions of L-[1-C-14]leucine in the postabsorptive state while receiving in a randomized order an enteral infusion of saline on one day or L-glutamine (800 mu mol . kg(-1). h(-1), equivalent to 0.11 g N/kg) on the other day. Seven additional subjects were studied using the same protocol except they received isonitrogenous infusion of glycine. The rates of leucine appearance (R(aLeu)), an index of protein degradation, leucine oxidation (Ox(Leu)), and nonoxidative leucine disposal (NOLD), an index of protein synthesis, were measured using the C-14 specific activity of plasma alpha-ketoisocaproate and the excretion rate of (CO2)-C-14 in breath. During glutamine infusion, plasma glutamine concentration doubled (673+/-66 vs. 1,184+/-37 mu M, P