Fraga Fuentes M D, de Juana Velasco P, Pintor Recuenco R
Servicio de Farmacia, Hospital Severo Ochoa, Madrid, España.
Nutr Hosp. 1996 Jul-Aug;11(4):215-25.
The advances in the field of nutritional support have made certain nutrients very relevant, which, although they have been known for a long time, at present represent an important chapter in nutrition, entering into what is known as "nutritional pharmacology". Among these nutrients is glutamine, an amino acid classified as non-essential, but which in certain circumstances may become to be considered as an "essential nutrient". In the present review, a review is made of its metabolic role, synthesis and degradation, metabolic routes and functions under normal conditions as well as under critical conditions. It is known that glutamine stimulates the synthesis and inhibits the degradation of proteins, it is an important vehicle for the transport of nitrogen and carbon within the tissues, it stimulates the synthesis of hepatic glycogen, it is an energy source for cell division, for the growth of different cells of rapid replication, such as enterocytes, colonocytes, and fibroblasts, as well as for other cells of the immune system, such as lymphocytes and macrophages. Thus its role in the maintenance of structure, in metabolism and function of the intestinal mucosa, and in dysfunctions of the immune system. In parenteral nutrition, at present there are no preparations which include it, given the stability problems which it presents, although attempts have been made to resolve this, using different possibilities, such as di-peptides. However, in enteral nutrition, the diets tend to include it, although in a small proportion. Nevertheless, having recognized its beneficial role in a certain type of patients, at present there are diets which contain glutamine in higher doses, with the object of attempting to cover the increased demands of glutamine which shall arise in these situations. The inclusion of glutamine in nutritional therapy is supported by multiple studies which reflect the beneficial effect of this nutrient, both in enteral nutrition as in parenteral nutrition.
营养支持领域的进展使某些营养素变得非常重要，这些营养素虽然早已为人所知，但目前在营养领域代表着重要的一章，进入了所谓的“营养药理学”范畴。这些营养素中包括谷氨酰胺，一种被归类为非必需氨基酸，但在某些情况下可能会被视为“必需营养素”。在本综述中，对其代谢作用、合成与降解、正常及危急情况下的代谢途径和功能进行了综述。已知谷氨酰胺能刺激蛋白质的合成并抑制其降解，是组织内氮和碳运输的重要载体，能刺激肝糖原的合成，是细胞分裂、快速复制的不同细胞（如肠上皮细胞、结肠细胞和成纤维细胞）以及免疫系统的其他细胞（如淋巴细胞和巨噬细胞）生长的能量来源。因此，它在维持肠道黏膜结构、代谢和功能以及免疫系统功能障碍方面发挥着作用。在肠外营养中，由于谷氨酰胺存在稳定性问题，目前尚无包含它的制剂，尽管已尝试通过不同可能性（如二肽）来解决这一问题。然而，在肠内营养中，饮食往往会包含谷氨酰胺，尽管比例较小。尽管如此，鉴于已认识到其在特定类型患者中的有益作用，目前有含较高剂量谷氨酰胺的饮食，旨在试图满足这些情况下谷氨酰胺增加的需求。多项研究支持在营养治疗中加入谷氨酰胺，这些研究反映了这种营养素在肠内营养和肠外营养中的有益效果。
