INVESTIGATIONS OF PROTEIN-METABOLISM IN HUMAN-PREGNANCY - THE TERM FETUS AND PLACENTA STUDIED USING STABLE ISOTOPE LABELED AMINO-ACIDS
INVESTIGATIONS OF PROTEIN-METABOLISM IN HUMAN-PREGNANCY - THE TERM FETUS AND PLACENTA STUDIED USING STABLE ISOTOPE LABELED AMINO-ACIDS
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DOI：
10.1016/0261-5614(91)90119-w
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发表时间：
1991-01-01
影响因子：
6.3
通讯作者：
CHIEN, PFW
中科院分区：
文献类型：
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作者：
CHIEN, PFW
极低出生体重早产儿通常需要通过全胃肠外营养喂养。本研究旨在为胎儿营养提供更深入的见解和科学数据，以便为新生儿提供更合理和科学的肠外营养。本文介绍了利用稳定同位素标记的氨基酸smallcap β-L-[1- 13 C]亮氨酸、smallcap β-L-[15 N]苯丙氨酸和smallcap β-L-[15 N]丙氨酸来测定胎儿对氨基酸的摄取、胎儿CO2产生率、胎盘蛋白合成率和胎儿全身蛋白质周转率的研究。根据目前新生儿的Vamin 9（Kabi Vitrum）推荐剂量，亮氨酸和苯丙氨酸的供应率分别为胎盘脐带摄取量的39%和86%。由于这两种氨基酸都是必需的，它们只能通过喂养来获得。这表明，Vamin 9和类似溶液向胃肠外喂养的婴儿提供的此类氨基酸量不足。结果还表明，健康新生儿的肝脏应该有足够的代谢能力来羟化苯丙氨酸，并防止高苯丙氨酸血症，这在胃肠外喂养的婴儿中已有报道。然而，这种代谢能力在早产儿中可能受损。
Very low birth weight pre-term infants commonly require feeding by total parenteral nutrition. This study aimed to provide further insight and scientific data on foetal nutrition in order that provision of parenteral nutrition for neonates can be put on a more rational and scientific basis. Studies using the stable isotope labelled amino acids smallcap˜L-[1-13C]leucine, smallcap˜L-[15N]phenylalanine and smallcap˜L-[15N]alanine to measure foetal uptake of amino acids, rate of foetal CO2production and fractional rate of placental protein synthesis and of foetal whole body protein turnover, are presented. Based on current recommended dosage for Vamin 9 (Kabi Vitrum) for newborn infants, the rate of supply of leucine and phenylalanine was found to be 39 and 86% of umbilical uptake from the placenta. As both these amino acids are essential, they can only be obtained through feeding. This suggests that Vamin 9 and similar solutions provide insufficient amounts of such amino acids to parenterally fed infants. Results also suggest that there should be sufficient metabolic capacity in the livers of healthy newborn infants to hydroxylate phenylalanine and prevent hyperphenylalaninaemia that has been reported in parenterally fed infants. However, this metabolic capacity may be impaired in pre-term neonates.