Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB T6G 2H9, Canada.
Appl Physiol Nutr Metab. 2011 Jun;36(3):405-11. doi: 10.1139/h11-035. Epub 2011 May 16.
L-arginine (2-amino-5-guanidinovaleric acid) is a conditionally essential amino acid. Intravenous (IV) administration of l-arginine invokes a large metabolic (nitrate/nitrite (NO(x))) and hormonal (growth hormone (GH), insulin-like growth factor 1 (IGF-1), and insulin) response; however, research examining oral l-arginine supplementation is conflicting, potentially owing to dose. The purpose of this study was examine a low and high dose of oral l-arginine on blood l-arginine, NO(x), GH, IGF-1, and insulin response. Fourteen physically active males (age: 25 ± 5 years; weight: 78.0 ± 8.5 kg; height: 179.4 ± 4.7 cm) volunteered to be in a randomized, double-blind, repeated-measures study. Following an overnight fast, an IV catheter was placed in a forearm vein and a resting blood sample was drawn at ∼0800 hours. Each subject was then provided 1 of 3 treatment conditions (placebo, low (0.075 g·kg(-1) of body mass), or high (0.15 g·kg(-1) of body mass of l-arginine)). Blood samples were drawn at 30, 60, 90, 120, and 180 min after consumption. l-arginine plasma concentrations significantly increased (p < 0.001) to a similar level at any time point in both the low- and high-dose conditions; there was no change over time in the placebo condition. There was no significant difference between conditions for NO(x), GH, IGF-1, or insulin. Based on these findings, a low dose of l-arginine was just as effective at increasing plasma l-arginine concentrations as a high dose; however, neither dose was able to promote a significant increase in NO(x), GH, IGF-1, or insulin at rest.
精氨酸（2-氨基-5-胍基戊酸）是一种条件必需氨基酸。静脉内（IV）给予精氨酸会引起较大的代谢（硝酸盐/亚硝酸盐（NO（x）））和激素（生长激素（GH），胰岛素样生长因子 1（IGF-1）和胰岛素）反应；然而，研究口服精氨酸补充剂的结果存在矛盾，这可能是由于剂量的原因。本研究的目的是研究低剂量和高剂量口服精氨酸对血液精氨酸，NO（x），GH，IGF-1和胰岛素反应的影响。十四名身体素质良好的男性（年龄：25 ± 5 岁；体重：78.0 ± 8.5kg；身高：179.4 ± 4.7cm）自愿参加了一项随机，双盲，重复测量的研究。在禁食过夜后，在前臂静脉中放置静脉导管，并在大约 0800 小时抽取静息血样。然后，每个受试者接受 3 种治疗条件之一（安慰剂，低（0.075g·kg（-1）的体重）或高（0.15g·kg（-1）的体重精氨酸））。在消耗后 30、60、90、120 和 180 分钟抽取血样。在低剂量和高剂量条件下，任何时间点的精氨酸血浆浓度均显著增加（p < 0.001），达到相似水平；安慰剂条件下没有随时间的变化。NO（x），GH，IGF-1或胰岛素在条件之间没有差异。根据这些发现，低剂量的精氨酸增加血浆精氨酸浓度的效果与高剂量相同；然而，两种剂量均不能在休息时显着增加 NO（x），GH，IGF-1或胰岛素。
