Glutamine supplementation in catabolic illness.
Glutamine supplementation in catabolic illness.
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分解代谢疾病中的谷氨酰胺补充剂。
DOI：
10.1093/ajcn/64.4.645
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Ziegler,TR
中科院分区：
文献类型：
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作者：
Ziegler,TR
组织特异性营养素的给药越来越多地被研究作为一种方法，以提高专门的肠内和肠外营养支持的疗效。许多动物研究和临床研究已经评估了补充谷氨酰胺的饮食的代谢和临床作用（1）。谷氨酰胺是血浆和机体中含量最丰富的氨基酸，在骨骼肌池、内脏床、肾脏和其他组织之间表现出动态的器官间代谢。谷氨酰胺是一个主要参与者在胚胎发生，RNA和DNA的合成，和酸碱平衡。它被用作快速复制组织（如肠粘膜和免疫系统细胞）的主要燃料和底物（1-3）。来自人类和动物研究的数据都支持谷氨酰胺在分解代谢疾病期间成为条件性必需的概念（1-3）。在分解代谢应激的动物模型中，肠内和/或肠外谷氨酰胺补充剂明显改善了重要的终点，如氮潴留、肠粘膜生长和修复、肠道屏障功能、免疫细胞数量和功能、抗感染性和动物存活率（1，2）。因此，谷氨酰胺似乎是几种氨基酸中的一种，包括组氨酸、精氨酸、牛磺酸和半胱氨酸，它们在人类营养中是半必需或条件必需的（4）。在本期杂志中，詹森等人（5）描述了一项双盲、随机、谷氨酰胺强化肠内管饲与标准低谷氨酰胺肠内管饲的前瞻性对照试验谷氨酰胺肠内管喂养在重症监护病房（ICU）的危重成人。临床匹配的患者在ICU入院后10天内进行研究，多发性创伤或头部损伤。对照组和实验组在ICU入院后< 48 h开始管饲。饮食是等能和等氮的，不同的只是在一定的非必需酸的量用于取代谷氨酰胺氮。饮食之间的主要差异是富含谷氨酰胺的实验配方中的谷氨酰胺含量增加了近6倍，其提供了28.9%的饮食蛋白质摄入量作为L-谷氨酰胺（0.3 g/kg）。d '），而对照低谷氨酰胺饮食中的饮食蛋白为5.0%（5）。使用富含谷氨酰胺的饮食并没有改变全身炎症或分解代谢应激的指数，随着时间的推移，各组的指数都有类似的下降。对照组和实验组的氮平衡、血清白蛋白和前白蛋白浓度也保持相似（5）。在整个研究期间，两个研究组均保持负氮平衡。这显示了实现自动化的困难，
The administration of tissue-specific nutrients is increasingly being investigated as an approach to enhance the efficacy of specialized enteral and parenteral nutrition support. Numerous animal studies and clinical investigations have evaluated the metabolic and clinical effects of diets supplemented with glutamine (1). Glutamine is the most abundant amino acid in plasma and the body and it exhibits dynamic interorgan metabolism between skeletal muscle pools, the splanchnic bed, kidney, and other tissues. Glutamine is a major participant in gluconeogenesis, RNA and DNA synthesis, and acid-base balance. It is used as a major fuel and substrate in rapidly repli-cating tissues such as the intestinal mucosa and cells of the immune system (1-3). Data from both human and animal studies support the concept that glutamine becomes condition-ally essential during catabolic illness (1-3). Enteral and/or parenteral glutamine supplementation in animal models of catabolic stress clearly improves important end points, such as nitrogen retention, intestinal mucosal growth and repair, gut barrier function, immune cell number and function, infection resistance, and animal survival (1, 2). Thus, glutamine appears to be one of several amino acids, including histidine, arginine, taurine, and cysteine, which are semiessential or conditionally essential in human nutrition(4).In this issue of the Journal, Jensen et al (5) describe the metabolic results of a double-blind, randomized, prospective controlled trial of glutamine-enriched enteral tube feedings compared with standard low-glutamine enteral tube feedings in critically ill adults in an intensive care unit (ICU). Clinically matched patients were studied during a l0-d period after ICU admission for multiple trauma or head injury. Control and experimental tube feedings were started< 48 h after ICU admission. The diets were isoenergetic and isonitrogenous and differed only in the amount of certain nonessential acids used to replace glutamine nitrogen. The major difference between the diets was a nearly six-fold increase in glutamine content in the glutamine-enriched experimental formula, which provided 28.9% of dietary protein intake as L-glutamine(0.3 g kg‘. d ‘) compared with 5.0% of the dietary protein in the control low-glutamine diet (5). Use of the glutamine-enriched diet did not alter indexes of systemic inflammation or catabolic stress, which declined similarly in each group over time. Nitrogen balance and serum albumin and prealbumin concentrations also remained similar in the control and experimental groups (5). Both study groups remained in negative nitrogen balance throughout the study period. which shows the difficulty in achieving anabolism in