ABSTRACT
Glutamine (Gln), the most abundant amino acid in the body, serves as an important metabolic intermediate, signaling molecule, and nutrient. Gln is considered to be a conditionally essential amino acid. Under stress conditions, such as trauma, infection, or sepsis, cells and tissues in the immune system increase the consumption of Gln. This chapter focuses on Gln effects on gut, provides a summary of recent studies and applications of Gln supplementation including long-term observations in neonates, and also discusses studies of Gln dipeptides. Combination of arginine and Gln as a dipeptide (Arg-Gln) has been used to take advantage of both amino acids and overcome the drawbacks of free Gln. Studies in a neonatal mouse model showed that intraperitoneal or enteral administration of Arg-Gln dipeptide reduced abnormal retinal neovascularization and vascular leakage, pulmonary or intestinal injury induced by hyperoxia.
