Maintaining muscle protein anabolism after a metabolic stress: role of dextrose vs. amino acid availability.
Maintaining muscle protein anabolism after a metabolic stress: role of dextrose vs. amino acid availability.
复制标题
代谢应激后维持肌肉蛋白质合成代谢：葡萄糖与氨基酸可用性的作用。
DOI：
10.1152/ajpendo.1997.272.1.e36
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Flakoll,PJ
中科院分区：
文献类型：
--
作者：
Borel,MJ;Williams,PE;Jabbour,K;Hibbard,JC;Flakoll,PJ
研究了氨基酸 (AA) 与葡萄糖 (D) 的慢性低热量肠外输注对全身代谢应激后蛋白质稳态的影响。多导管杂种狗通过 4 天禁食进行代谢挑战，然后进行 4 天静脉输注盐水（S，n = 8）、D（n = 8）或等热量 AA（n = 7）。尽管在禁食期间，S (-0.37 +/- 0.05)、D (-0.28 +/- 0.03) 和 AA (-0.37 +/- 0.04) 的氮平衡 (g.kg.1.day-1) 也同样呈负值，但 AA (-0.06 +/- 0.04) 的负值程度 (P < 或 = 0.05) 低于 D (-0.20 +/- 0.04) 0.03) 或 S (-0.23 +/- 0.04) 营养输注期间。 AA 导致后肢净摄取，D 导致必需 AA 的净后肢释放（570 +/- 261 对比 -248 +/- 59 nmol.kg-1.min-1）。 S 和 D 输注导致后肢肌肉蛋白净损失（分别为 -37 +/- 24 和 -89 +/- 33 微克.kg-1.min-1，与 AA 相比，P < 或 = 0.05），而肠外 AA 导致净沉积（169 +/- 62 微克.kg-1.min-1）（使用 L-[ring-2H5]苯丙氨酸测量）。因此，代谢应激后低热量肠外 D 输注不利于氮保存，因为与 S 输注相比，全身净氮损失、骨骼肌蛋白分解代谢和后肢 AA 释放并未减弱。相反，低热量 AA 输注可以保留全身和肌肉的蛋白质储存。
The effect of chronic hypocaloric parenteral infusions of amino acids (AA) vs. dextrose (D) on protein homeostasis after a generalized metabolic stress was examined. Multicatheterized mongrel dogs were metabolically challenged by a 4-day fast and then administered a 4-day intravenous infusion of saline (S, n = 8), D (n = 8), or isocaloric AA (n = 7). Although nitrogen balance (g.kg.1.day-1) was similarly negative with S (-0.37 +/- 0.05), D (-0.28 +/- 0.03), and AA (-0.37 +/- 0.04) during the fasting period, it was less negative (P < or = 0.05) with AA (-0.06 +/- 0.04) than with D (-0.20 +/- 0.03) or S (-0.23 +/- 0.04) during nutrient infusion. AA resulted in net hindlimb uptake and D in net hindlimb release of essential AA (570 +/- 261 vs. -248 +/- 59 nmol.kg-1.min-1). Whereas S and D infusions led to net hindlimb muscle protein loss (-37 +/- 24 and -89 +/- 33 micrograms.kg-1.min-1, respectively, P < or = 0.05 vs. AA), parenteral AA resulted in net deposition (169 +/- 62 micrograms.kg-1.min-1) as measured using L-[ring-2H5]phenylalanine. Thus hypocaloric parenteral D infusion after a metabolic stress does not favor nitrogen conservation, because net whole body nitrogen loss, skeletal muscle protein catabolism, and hindlimb AA release were not blunted compared with S infusion. Conversely, hypocaloric AA infusion preserves whole body and muscle protein stores.