Glutamine supplementation in cancer patients

OBJECTIVES: Three series of studies investigated whether 1) glutamine defic iency occurs in tumor-bearing rats, 2) glutamine supplementation improves p rotein metabolism during chemotherapy in tumor-bearing rats, and 3) oral gl utamine supplement improves systemic immune and gut-barrier function in pat ients with esophageal cancer receiving radiochemotherapy. METHODS: In the animal studies, AH109A hepatoma cells or Yoshida sarcoma ce lls were inoculated into male Donryu rats to induce tumors. Glutamine produ ction was measured by U-C-14-glutamine infusion and the conversion of argin ine to glutamine was measured by infusion of U-C-14-arginine. The effect of glutamine on protein metabolism was investigated by 1-C-14-leucine infusio n. In the clinical study, 13 patients with esophageal cancer were randomize d into two groups, control and glutamine supplemented (30 g/d), for 4 wk. RESULTS: Glutamine levels in plasma and skeletal muscle were decreased in t umor-bearing rats, although glutamine production and the conversion of argi nine to glutamine were increased. Glutamine-supplemented total parenteral n utrition reduced whole-body protein breakdown rate during chemotherapy in t umor-bearing rats. Oral supplementation of glutamine to the patients with e sophageal cancer enhanced lymphocyte mitogenic function and reduced permeab ility of the gut during radiochemotherapy. CONCLUSIONS: Glutamine depletion in host tissues occurs in tumor-bearing ra ts. Glutamine supplementation can attenuate loss of protein in the muscle i n tumor-bearing animals and protect immune and gut-barrier function during radiochemotherapy in patients with advanced cancer. Nutrition 2001;17: 766- 768. (C) Elsevier Science Inc. 2001.