Duffy B, Gunn T, Collinge J, Pencharz P
Pediatr Res. 1981 Jul;15(7):1040-4. doi: 10.1203/00006450-198107000-00013.
Net nitrogen retention (NNR) and rates of whole-body protein turnover (Q), synthesis, and breakdown (B) were measured in 24 intravenously fed premature infants, birthweight less than 1600 g, at the end of the first week of life. Four regimes were used: Amigenglucose +/- Intralipid; Vamin-glucose +/- Intralipid. Mean protein intake was 2.7 g/kg/day. Mean energy intakes were 68 to 98 kcal/kg/day. Vamin was a better protein source (p less than 0.01), evidence by a higher NNR; 72 +/- 2%, cf. 56 +/- 4% at high-energy intakes. The high-energy intake also improved (p less than 0.01) protein retention (NNR); 64 cf. 50%. Infants receiving 2.9 g of Vamin (394 mg N)/ kg/day and 85 kcal/kg/day of nonprotein intake retained nitrogen at intrauterine rates (282 +/- 7 mg/kg/day). Diet had no effect on Q, synthesis, or B. However, the protein source had a significant effect (p less than 0.01) on the fraction of N-flux coming from protein breakdown (B/Q); 71.7% for Vamin, cf. 77.1% for Amigen. Similarly, energy intake had a significant effect (p less than 0.01) on the fraction N-flux utilized for protein synthesis (S/Q); 91.3% high energy cf. 87.0% low energy. These results suggest that an increased energy intake improved N-retention by enhancing amino acid reutilization for protein synthesis, whereas a higher quality protein improved N-retention by limiting protein breakdown..3% high energy cf. 87.0% low energy. These results suggest that an increased energy intake improved N-retention by enhancing amino acid reutilization for protein synthesis, whereas a higher quality protein improved N-retention by limiting protein breakdown..3% high energy cf. 87.0% low energy. These results suggest that an increased energy intake improved N-retention by enhancing amino acid reutilization for protein synthesis, whereas a higher quality protein improved N-retention by limiting protein breakdown.
对24名出生体重小于1600克的静脉喂养早产婴儿在出生后第一周结束时测量了净氮保留量（NNR）以及全身蛋白质周转率（Q）、合成率和分解率（B）。采用了四种方案：氨基酸葡萄糖±脂肪乳剂；凡命 - 葡萄糖±脂肪乳剂。平均蛋白质摄入量为2.7克/千克/天。平均能量摄入量为68至98千卡/千克/天。凡命是更好的蛋白质来源（p<0.01），净氮保留量更高即为证据；高能摄入时为72±2%，相比之下为56±4%。高能摄入也改善了（p<0.01）蛋白质保留（净氮保留量）；分别为64%和50%。接受2.9克凡命（394毫克氮）/千克/天和85千卡/千克/天非蛋白质摄入量的婴儿以宫内速率（282±7毫克/千克/天）保留氮。饮食对Q、合成或B没有影响。然而，蛋白质来源对来自蛋白质分解的氮通量比例（B/Q）有显著影响（p<0.01）；凡命为71.7%，相比之下爱咪蛋白为77.1%。同样，能量摄入对用于蛋白质合成的氮通量比例（S/Q）有显著影响（p<0.01）；高能时为91.3%，相比之下低能时为87.0%。这些结果表明，能量摄入增加通过增强氨基酸再利用以进行蛋白质合成来改善氮保留，而更高质量的蛋白质通过限制蛋白质分解来改善氮保留。高能时为91.3%，相比之下低能时为87.0%。这些结果表明，能量摄入增加通过增强氨基酸再利用以进行蛋白质合成来改善氮保留，而更高质量的蛋白质通过限制蛋白质分解来改善氮保留。高能时为91.3%，相比之下低能时为87.0%。这些结果表明，能量摄入增加通过增强氨基酸再利用以进行蛋白质合成来改善氮保留，而更高质量的蛋白质通过限制蛋白质分解来改善氮保留。
