IMMUNOMODULATORY EFFECTS OF ACUTE EXERCISE BOUT IN SEDENTARY AND TRAINED RATS

The immune response to acute exercise after long-term training was eva luated in rats. After 10 wk of exercise training on a drum exerciser, both sedentary control and trained groups ran with the intensity of 70 % of peak oxygen consumption (VO2peak) for 10 min immediately before s acrifice. The mitogenic activity of spleen lymphocytes in trained grou p to staphylococcal enterotoxin B, a polyclonal T cell activator, decr eased as compared to the sedentary control following acute exercise. H owever, proliferative response to lipopolysaccharide, a B cell mitogen , was augmented. Furthermore, the interleukin-2 production was reduced in the trained group. The lymphocyte subpopulations in the spleen and the peripheral blood lymphocytes were analyzed by flow cytometry. Alt hough the tendency of changes in some populations was observed in trai ned vs untrained groups, no statistically significant difference was m anifested. The serum levels of both norepinephrine and epinephrine inc reased immediately after acute exercise. The increase in serum lactate concentration was observed following acute exercise in sedentary cont rol, but less prominent in the trained group.