Influence of glutamine and branched chain amino acids on the jejunal atrophy associated with parenteral nutrition

Infusions of conventional parenteral nutrients (CPN) are associated with gut atrophy. This may be due to the absence of glutamine in such solutions. Although glutamine is a preferred gut nutrient, it is excluded from CPN because it is unstable at room temperature. This problem may be circumvented either directly by the infusion of fresh solutions of glutamine, or indirectly by the infusion of branched chain amino acids (BCAA). We evaluated the effect of infusing either glutamine, BCAA, or glutamine plus BCAA-enriched CPN on the rat jejunum. Sixty male Wistar rats were randomized to receive 6 days of either conventional parenteral nutrition (CPN), CPN plus 1.5% glutamine (GLN), CPN plus 2% BCAA (BCAA), CPN plus 0.8% BCAA and 1.0% glutamine (GLN/BCAA), or a normal oral diet (Chow). Standardized segments of jejunum were then removed for assessment. Compared with the CPN group, both the GLN/BCAA and the BCAA groups had greater mucosal weights (P less than 0.05) and mucosal protein concentrations (P less than 0.05), the GLN/BCAA group had greater jejunal weights (P less than 0.05), and the GLN group had an increased jejunal weight (P less than 0.05) and a higher crypt cell production rate (P less than 0.05). We conclude that the infusion of glutamine or BCAA-enriched parenteral nutrition improves jejunal morphology compared with conventional parenteral nutrition.