Effect of enteral glutamine on leucine, phenylalanine and glutamine metabolism in hypercortisolemic subjects

enteral glutamine on leucine, phenylalanine and glutamine metabolism in hypercortisolemic subjects. Am J Physiol Endocrinol Metab 278: E817–E824, 2000.—The effect of enteral Gln on protein and Gln metabolism was investigated during experimental hypercortisolemia. Four groups of sub-jects that had received corticosteroids and either enteral Gln (0.5 g·kg21 ·day21 for 2 days) or isonitrogenous Ala-Gly were studied in a fasted or in a fed state. In either state, enteral Gln, compared with Ala-Gly, induced no statistically signifi-cant change in the endogenous rate of Leu appearance, an index of proteolysis, Leu oxidation, and nonoxidative Leu disposal, an index of protein synthesis, as studied by kinetics of [1-13C]Leu. Similar data were obtained from kinetics of [2H5]Phe, resulting in an unchanged protein balance in both cases. In contrast, enteral Gln significantly decreased th