Effect of parenteral glutamine peptide supplements on muscle glutamine loss and nitrogen balance after major surgery.

Twelve patients admitted for elective resection of carcinoma of colon or rectum were allocated at random to experimental and control groups (six in each) and received a total parenteral nutrition regimen providing 230 mg N/kg and 166 KJ/kg daily over the first 5 postoperative days. In the experimental group the parenteral fluid was supplemented with a synthetic glutamine-containing dipeptide, L-alanyl-L-glutamine (54 mg peptide-N/kg per day) and the control group received corresponding amounts of alanine-N and glycine-N. On each postoperative day nitrogen balance was better in the experimental group; mean daily nitrogen balance with alanyl-glutamine was -1.5 (SE 0.4) g N/day and with the control solution -3.6 (0.2) g N/day. The cumulative nitrogen balances on the fifth postoperative day were -7.1 (2.2) and -18.1 (1.7) g N, respectively. With the peptide-containing solution intramuscular glutamine concentration remained close to the preoperative value whereas with the control solution it decreased from 19.7 (SE 0.9) to 12.0 (0.6) mmol/l intracellular water.