GLUTAMINE METABOLISM IN HUMAN NEONATES

本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上皮细胞的重要燃料，可能是早产儿和手术应激婴儿不可缺少的氨基酸。因此，确定这些婴儿合成谷氨酰胺的能力和调节谷氨酰胺从现有的身体蛋白质的释放是重要的。在这些特别脆弱的婴儿中，补充谷氨酰胺可能在支持最佳蛋白质积累、肠道损伤恢复和免疫功能方面发挥关键作用。本提案的具体目的是确定早产和手术应激如何改变新生谷氨酰胺合成和谷氨酰胺从体内蛋白释放的速率：1)基础状态2)响应肠外营养的提供3)响应补充谷氨酰胺的肠外营养的提供。这些具体目标将使用稳定同位素示踪剂来实现。进行这些研究将提供对谷氨酰胺代谢的深入了解，并最终可能作为改善早产儿和手术应激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.