Glutamine supplementation prevents the decrease of mitogen response after a treadmill exercise in rats.
The effect of glutamine (Gln)-supplemented diet on mitogen response decreased immediately after a treadmill exercise was examined by measuring the proliferations of peripheral blood lymphocytes (PBL) with phytohemagglutinin (PHA) and concanavalin A (ConA) in male Fisher rats. Although the plasma Gln concentration was significantly decreased in the control group immediately after a treadmill exercise (20 m/min, 60 min) compared to rested rats, plasma Gln concentration of rats fed Gln-supplemented diet for 3 weeks was significantly higher than that of control group in resting and was not significantly decreased even immediately after a treadmill exercise. In addition, proliferation of PBL with PHA or ConA and interleukin 2 (IL2) production were also significantly decreased immediately after a treadmill exercise in control group. On the contrary, their functions were almost maintained in Gln-supplemented group even immediately after a treadmill exercise. PBL from rats fed Gln-supplemented diet showed a higher response to mitogens such as PHA and ConA compared to the control group. Furthermore, their PBL showed higher incorporation of [3H]Gln compared to that of the control group irrespective of treadmill exercise. These results indicate that the preventive effect of Gln-supplemented diet on mitogen response decreased after a treadmill exercise is due to an increased response to mitogen and increased uptake of Gln as sources of fuel and nucleotides to the immune cells.