Duffy B, Pencharz P
Pediatr Res. 1986 Jan;20(1):32-5. doi: 10.1203/00006450-198601000-00008.
Nitrogen retention and rates of whole body amino nitrogen flux, protein synthesis, and breakdown were measured in 18 neonates during the 72 h immediately postsurgery. The infants were all intravenously fed with a crystalline amino acid source (Vamin), glucose, and Intralipid The infants were divided into two groups based on amino acid intake: either 2.3 SD 0.4 g or 3.9 SD 0.5 g/kg/day. Nonprotein energy intakes were similar and averaged 81 kcal/kg/day. Group A (n = 11) retained 145 SD 110 mg N/kg/day, whilst group B (n = 7) retained 315 SD 93 mg N/kg/day (p less than 0.001). There were no differences seen in flux, synthesis or breakdown. However, group B had significantly higher net protein synthesis rates (synthesis-breakdown) (p less than 0.01). The improved nitrogen utilization in group B was achieved principally by a reduction in endogenous protein breakdown. There were no differences between the two groups in urinary creatinine or 3-methylhistidine excretion. Since these two parameters reflect skeletal muscle turnover the differences between groups in nitrogen retention and turnover appear to be mediated through visceral protein.
在18名新生儿术后立即的72小时内，测量了氮潴留以及全身氨基氮通量、蛋白质合成和分解的速率。所有婴儿均通过静脉输注结晶氨基酸源（凡命）、葡萄糖和英脱利匹特进行喂养。根据氨基酸摄入量，将婴儿分为两组：分别为2.3±0.4g或3.9±0.5g/（kg·天）。非蛋白质能量摄入量相似，平均为81kcal/（kg·天）。A组（n=11）的氮潴留量为145±110mg/（kg·天），而B组（n=7）为315±93mg/（kg·天）（p<0.001）。在通量、合成或分解方面未观察到差异。然而，B组的净蛋白质合成率（合成-分解）显著更高（p<0.01）。B组氮利用的改善主要是通过内源性蛋白质分解的减少实现的。两组在尿肌酐或3-甲基组氨酸排泄方面没有差异。由于这两个参数反映骨骼肌更新，两组在氮潴留和更新方面的差异似乎是通过内脏蛋白介导的。
