EFFECT OF EXHAUSTIVE EXERCISE STRESS ON THE CYTOKINE RESPONSE

Fifteen athletes were investigated 24 h before, 1 h after, and 20 h af ter an exhaustive exercise stress test (mean duration 68 min). Testing for cytokines was done in serum, urine, and the supernatants of whole blood cell cultures, which were stimulated with lipopolysac charide ( LPS), concanavalin A (Con A), or phythaemagglutinin (PHA). Elevated le vels of interleukin 6 (IL-6) and soluble IL-2 receptor (sIL-2R) were f ound I h after the run in both serum and urine samples. TNF-alpha in s erum was also increased, whereas IL-2 in urine was decreased after the exercise. All other testings in serum and urine (including IFN-gamma) gave borderline or negative results. In cell cultures, the LPS-induce d release of the inflammatory cytokines TNF-alpha, IL-1, and IL-6 was suppressed 1 h after exercise. Also, the Con-A-induced and LPS-induced release of IFN-gamma, and the PHA-induced release of IL-2 were suppre ssed 1 h after exercise. In contrast, Con-A-induced release of IL-2 wa s mildly increased after the run. We conclude that exercise of the int ensity and duration described here causes an activation of the immune system, which is immediately counter-regulated. Twenty hours after the exercise, most of the observed changes were back to pre-exercise leve ls, indicating only a short duration for this suppressive counter-regu lation.