COMPETITIVE SUSTAINED EXERCISE IN HUMANS, LYMPHOKINE-ACTIVATED KILLER-CELL ACTIVITY, AND GLUTAMINE - AN INTERVENTION STUDY

This study examined whether oral glutamine supplementation abolishes s ome of the exercise-induced changes in lymphocyte functions following long-term intense exercise. A roup of 16 marathon runners participatin g in The Copenhagen Marathon 1996 were placed randomly in either a pla cebo (II = 7) or a glutamine receiving group (n = 9). Each subject rec eived four doses of either placebo or glutamine (100 mg . kg(-1)) admi nistered at 0, 30, 60, and 90-min post-race. In the placebo group the plasma glutamine concentrations were lower than pre-race values during the post-exercise period [mean 647 (SEM 32) compared to 470 (SEM 22) mu mol . l(-1) 90-min post-race, P < 0.05] whereas glutamine supplemen tation maintained the plasma glutamine concentration (at similar to 75 0 mu mol . l(-1)). Glutamine supplementation in vivo had no effect on the lymphokine activated killer (LAI() cell activity, the proliferativ e responses or the exercise-induced changes in concentrations or perce ntages of any of the leucocyte subpopulations examined. Glutamine addi tion in in vitro studies enhanced the proliferative response in both g roups. These data would suggest that decreased plasma,glutamine concen trations post-exercise are not responsible for exercise-induced decrea se in LAK activity and that the influence of glutamine in vitro is not dependent on the plasma glutamine concentration at the time of sampli ng.