To evaluate if exhaustion after maximal exercise suppresses the immune system; ten
healthy male oarsmen (maximal oxygen uptake, 5.7 ± 0.2 l · min-1 ; mean and SE) performed a six minute "all-out" bout on a rowing ergometer (394 ±
12 watt). Rowing increased the blood leucocyte count as reflected in the concentrations
of lymphocytes, monocytes, and neutrophils. Two hours after rowing the leucocyte and
neutrophil numbers remained elevated, while the lymphocyte count decreased below the
prevalue. The concentrations of cluster designation CD3+ (pan T), CD4+ (T subset),
CD8+ (T subset), CD19+ (B cells), and CD16+ natural killer (NK) cells increased during
rowing with the elevation in CD16+ cells being sevenfold. Only the concentration of
CD3+ and CD8+ cells decreased below prevalues two hours after exercise. The lymphokine
activated killer (LAK) cell activity of blood mononuclear cells (BMNC), and the NK
cell activity of BMNC ( % lysis per fixed number of BMNC), either unstimulated or
stimulated with interleukin-2, interferon-alfa or indomethacin, also increased in
response to rowing, and returned to the prevalues after two hours. In contrast, the
BMNC proliferative responses did not change significantly. The evaluation of NK and
LAK cell activities, and the proliferative responses of BMNC suggest that six minute
maximal exercise does not suppress the immune response during recovery, even when
a large muscle mass is involved.
Key words
Natural killer cells - lymphokine activated killer cells - lymphocyte proliferative
response - rowing
