Abstract
OBJECTIVE: To investigate whether the administration of different glutamine-containing dipeptides, glycyl-l-glutamine (GLY-GLN) and l-alanyl-l-glutamine, has a differing impact on perioperative immunomodulation. SUMMARY BACKGROUND DATA: Surgery leads to transitory immunosuppression, which is associated with decreased plasma glutamine (GLN) levels and increased susceptibility to infection and sepsis. A useful tool to detect immunocompetence is the ex vivo lipopolysaccharide (LPS)-stimulated tumor necrosis factor alpha (TNF-alpha) secretion in whole blood. METHODS: Forty-five patients undergoing major abdominal surgery were randomized prospectively to receive 0.5 g/kg/24 h GLN dipeptides administered as GLY-GLN or as ALA-GLN or isonitrogenous Vamin (a GLN-free amino acid solution; control group) as a continuous infusion over 72 hours, starting 24 hours before surgery. Blood samples were collected before infusion, at the end of surgery, and 48 hours postoperatively to determine the TNF-alpha release into whole blood stimulated with LPS. Groups were compared by analysis of variance. RESULTS: The groups were comparable in age, gender distribution, and length of operative time. At the end of surgery a significant reduction in ex vivo LPS-stimulated TNF-alpha production was observed in all groups. In patients who received GLY-GLN, the induced TNF-alpha production was restored after 48 hours. CONCLUSIONS: In this study perioperative infusion of GLY-GLN reduced immunosuppression. The effect of GLN-containing dipeptides seems to be different when administered in glycine or alanine form.