Effects of flooding amino acids on incorporation of labeled amino acids into human muscle protein
Effects of flooding amino acids on incorporation of labeled amino acids into human muscle protein
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DOI：
10.1152/ajpendo.1998.275.1.e73
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发表时间：
1998-07-01
影响因子：
5.1
通讯作者：
Rennie, MJ
中科院分区：
文献类型：
--
作者：
Smith, K;Reynolds, N;Rennie, MJ
我们研究了洪水氨基酸的性质对示踪亮氨酸掺入人体骨骼肌活检样品的速率的影响。23名健康年轻男性（24.5 +/- 5.0岁，76.2 +/- 8.3 kg）分为4组或5组进行研究。首先，研究了用苯丙氨酸、苏氨酸或精氨酸（均为0.05 g/kg体重）驱替对示踪剂[C-13]亮氨酸掺入的影响。然后研究了用标记的[C-13]甘氨酸[0.1 g/kg体重，20原子百分比过量（APE）]和[C-13]丝氨酸（0.05 g/kg体重，15 APE）对同时输注的[C-13]亮氨酸掺入的影响。当给予大剂量的苯丙氨酸或苏氨酸时，示踪剂亮氨酸的掺入显著增加（分别从0.036%/h增加至0.067%/h和从0.037%/h增加至0.070%/h;每个P < 0.01）。然而，当精氨酸，甘氨酸，或丝氨酸作为一个洪水剂量，没有刺激示踪亮氨酸掺入可以观察到。这些结果与先前获得的结果一起表明，大剂量的个体必需氨基酸（而非非非必需氨基酸）能够刺激不断注入的示踪氨基酸掺入人肌肉蛋白。
We investigated the effects of the nature of the flooding amino acid on the rate of incorporation of tracer leucine into human skeletal muscle sampled by biopsy. Twenty-three healthy young men (24.5 +/- 5.0 yr, 76.2 +/- 8.3 kg) were studied in groups of four or five. First, the effects of flooding with phenylalanine, threonine, or arginine (all at 0.05 g/kg body wt) on the incorporation of tracer [C-13]leucine were studied. Then the effects of flooding with labeled [C-13]glycine [0.1 g/kg body wt, 20 atoms percent excess (APE)] and [C-13]serine (0.05 g/kg body wt, 15 APE) on the incorporation of simultaneously infused [C-13]leucine were investigated. When a large dose of phenylalanine or threonine was administered, incorporation of the tracer leucine was significantly increased (from 0.036 to 0.067 %/h and 0.037 to 0.070 %/h, respectively; each P < 0.01). However, when arginine, glycine, or serine was administered as a flooding dose, no stimulation of tracer leucine incorporation could be observed. These results, together with those previously obtained, suggest that large doses of individual essential, but not nonessential, amino acids are able to stimulate incorporation of constantly infused tracer amino acids into human muscle protein.