Abstract des Autors

This study was designed to examine the impact of exhaustive endurance exercise on a number of immune parameters of physically fit male subjects (VO2max 66.5+/-5.3 ml/min/kg) who performed tradmill exercise at 65% of their VO2max for 120 min. Serial blood samples were taken before, during and after exercise and changes in leukocyte and lymphocyte subset concentrations, immunoglobulin production in vitro, and natural killer (NK) cell response were measured. The exercise regimen was found to induce the well-known phenomenon of leukocytosis which consisted primarily of a granulocytosis and lymphocytosis. Among the lymphocyte subsets, peripheral pan T cells (CD3+) as well as helper (CD4+) and suppressor (CD8+) T cells were found to be elevated. A relatively smaller increase in CD4+ than CD8+ cells resulted in depressed CD4/CD8 ratios throughout the exercise period. After exercise, T cells declined progressively and, 2 h post-exercise, were less than 60% of their pre-exercise level. In contrast, the CD4/CD8 ratio demonstrated a progressive increase, thus representing a reversal in the pattern observed during exercise and a trend towards an elevated ratio during recovery. B cells (CD19+) were relatively unaffected by exercise, although IgM production by pokeweed mitogen-stimulated lymphocytes obtained from blood samples after 120 min of exercise was significantly depressed. NK cells were affected dramatically by exercise. Both CD16+ cell numbers and NK cytotoxicity were increased during exercise, followed by a persistent depression in the post-exercise period. The strenuous exercise induced a profound effect on NK cells as evidenced by a 40% depression of the NK cell count for as long as 7 days after the cessation of exercise. Our results provide direct kinetic evidence demonstrating that exhaustive exertion alters both lymphocyte distribution pattern and effector function, suggestive of possible exercise-induced immune compromise, particularly in the post-exercise recovery period. Verf.-Referat