Castell L M, Newsholme E A
University Department of Biochemistry, Oxford, United Kingdom.
Nutrition. 1997 Jul-Aug;13(7-8):738-42. doi: 10.1016/s0899-9007(97)83036-5.
Athletes undergoing intense, prolonged training or participating in endurance races suffer an increased risk of infection due to apparent immunosuppression. Glutamine is an important fuel for some cells of the immune system and may have specific immunostimulatory effects. The plasma glutamine concentration is lower after prolonged, exhaustive exercise: this may contribute to impairment of the immune system at a time when the athlete may be exposed to opportunistic infections. The effects of feeding glutamine was investigated both at rest in sedentary controls and after exhaustive exercise in middle-distance, marathon and ultra-marathon runners, and elite rowers, in training and competition. Questionnaires established the incidence of infection for 7 d after exercise: infection levels were highest in marathon and ultra-marathon runners, and in elite male rowers after intensive training. Plasma glutamine levels were decreased by approximately 20% 1 h after marathon running. A marked increase in numbers of white blood cells occurred immediately after exhaustive exercise, followed by a decrease in the numbers of lymphocytes. The provision of oral glutamine after exercise appeared to have a beneficial effect on the level of subsequent infections. In addition, the ratio of T-helper/T-suppressor cells appeared to be increased in samples from those who received glutamine, compared with placebo.
进行高强度、长时间训练或参加耐力赛的运动员，由于明显的免疫抑制，感染风险增加。谷氨酰胺是免疫系统某些细胞的重要燃料，可能具有特定的免疫刺激作用。长时间力竭运动后，血浆谷氨酰胺浓度会降低：这可能在运动员可能接触机会性感染时导致免疫系统受损。研究了在久坐对照者休息时以及在中长跑、马拉松和超级马拉松运动员以及精英赛艇运动员训练和比赛中的力竭运动后补充谷氨酰胺的效果。通过问卷调查确定运动后7天的感染发生率：马拉松和超级马拉松运动员以及精英男性赛艇运动员在高强度训练后的感染水平最高。马拉松跑步1小时后，血浆谷氨酰胺水平下降约20%。力竭运动后白细胞数量立即显著增加，随后淋巴细胞数量减少。运动后口服谷氨酰胺似乎对后续感染水平有有益影响。此外，与安慰剂相比，接受谷氨酰胺者样本中的辅助性T细胞/抑制性T细胞比例似乎有所增加。
