GLUTAMINE METABOLISM IN HUMAN NEONATES

这项建议的总体目标是阐明新生儿谷氨酰胺代谢的途径，并确定早产和手术应激如何改变这些途径。谷氨酰胺是淋巴细胞和肠道上皮细胞的重要燃料，可能是早产儿和手术应激婴儿不可或缺的氨基酸。因此，确定这些婴儿合成谷氨酰胺的能力以及调节体内现有蛋白质中谷氨酰胺的释放是很重要的。补充谷氨酰胺可能在支持这些特别脆弱的婴儿的最佳蛋白质积累、肠道损伤恢复和免疫功能方面发挥关键作用。这项建议的具体目的是确定早产儿和手术应激如何改变体内蛋白质中谷氨酰胺的从头合成和释放的速率：1)基础状态，2)对提供肠外营养的反应，3)对补充谷氨酰胺的肠外营养的反应。将使用稳定的同位素示踪剂来实现这些具体目标。进行这些研究将提供对谷氨酰胺代谢的洞察，并最终可能成为改善早产儿和手术应激性婴儿营养管理的基础。

The overall objective of this proposal is to elucidate the pathways of glutamine metabolism in neonates and to determine how prematurity and surgical stress alter these pathways. Glutamine, an important fuel for lymphocytes and intestinal epithelial cells, may be an indispensable amino acid in premature and surgically stressed infants. Consequently, determining the capacity of these infants to synthesize glutamine and the regulation of the release of glutamine from existing body protein is important. Glutamine supplementation may play a critical role in supporting optimal protein accretion, recovery from intestinal injury, and immune function in these particularly vulnerable infants. The specific aims of this proposal are to determine how rates of de novo glutamine synthesis and release of glutamine from body protein are altered by prematurity and surgical stress in: 1) the basal state 2) in response to the provision of parenteral nutrition and 3) in response to the provision of parenteral nutrition with supplemental glutamine. These specific aims will be pursued using stable isotope tracers. Performing these studies will provide insight into the metabolism of glutamine and ultimately, may serve as the basis for improved nutritional management of premature and surgically stressed infants.