Yoshida S, Kaibara A, Ishibashi N, Shirouzu K
Department of Surgery, Kurume University, School of Medicine, Fukuoka, Japan.
Nutrition. 2001 Sep;17(9):766-8. doi: 10.1016/s0899-9007(01)00629-3.
Three series of studies investigated whether 1) glutamine deficiency occurs in tumor-bearing rats, 2) glutamine supplementation improves protein metabolism during chemotherapy in tumor-bearing rats, and 3) oral glutamine supplement improves systemic immune and gut-barrier function in patients with esophageal cancer receiving radiochemotherapy.
In the animal studies, AH109A hepatoma cells or Yoshida sarcoma cells were inoculated into male Donryu rats to induce tumors. Glutamine production was measured by U-14C-glutamine infusion and the conversion of arginine to glutamine was measured by infusion of U-14C-arginine. The effect of glutamine on protein metabolism was investigated by 1-14C-leucine infusion. In the clinical study, 13 patients with esophageal cancer were randomized into two groups, control and glutamine supplemented (30 g/d), for 4 wk.
Glutamine levels in plasma and skeletal muscle were decreased in tumor-bearing rats, although glutamine production and the conversion of arginine to glutamine were increased. Glutamine-supplemented total parenteral nutrition reduced whole-body protein breakdown rate during chemotherapy in tumor-bearing rats. Oral supplementation of glutamine to the patients with esophageal cancer enhanced lymphocyte mitogenic function and reduced permeability of the gut during radiochemotherapy.
Glutamine depletion in host tissues occurs in tumor-bearing rats. Glutamine supplementation can attenuate loss of protein in the muscle in tumor-bearing animals and protect immune and gut-barrier function during radiochemotherapy in patients with advanced cancer.
三项系列研究旨在调查：1）荷瘤大鼠是否存在谷氨酰胺缺乏；2）补充谷氨酰胺是否能改善荷瘤大鼠化疗期间的蛋白质代谢；3）口服补充谷氨酰胺是否能改善接受放化疗的食管癌患者的全身免疫和肠道屏障功能。
在动物研究中，将AH109A肝癌细胞或吉田肉瘤细胞接种到雄性唐育大鼠体内以诱导肿瘤。通过输注U-14C-谷氨酰胺测量谷氨酰胺生成量，并通过输注U-14C-精氨酸测量精氨酸向谷氨酰胺的转化。通过输注1-14C-亮氨酸研究谷氨酰胺对蛋白质代谢的影响。在临床研究中，13例食管癌患者被随机分为两组，即对照组和补充谷氨酰胺组（30 g/天），为期4周。
荷瘤大鼠血浆和骨骼肌中的谷氨酰胺水平降低，尽管谷氨酰胺生成量以及精氨酸向谷氨酰胺的转化增加。补充谷氨酰胺的全胃肠外营养降低了荷瘤大鼠化疗期间的全身蛋白质分解率。对食管癌患者口服补充谷氨酰胺可增强淋巴细胞有丝分裂功能，并降低放化疗期间肠道的通透性。
荷瘤大鼠体内宿主组织存在谷氨酰胺消耗。补充谷氨酰胺可减轻荷瘤动物肌肉中的蛋白质损失，并在晚期癌症患者放化疗期间保护免疫和肠道屏障功能。
