INCREASED CIRCULATING CYTOKINE RECEPTORS AND EX-VIVO INTERLEUKIN-1 RECEPTOR ANTAGONIST AND INTERLEUKIN-1-BETA PRODUCTION BUT DECREASED TUMOR-NECROSIS-FACTOR-ALPHA PRODUCTION AFTER A 5-KM RUN

Background The purpose of this study was to examine the effect of a 5- km run on blood leucocytes, acute-phase proteins and cytokines. In add ition, cytokines were measured in the supernatants from whole-blood ce ll cultures incubated with lipolysaccharide (LPS). Methods Ten healthy , recreational trained, athletes (three women, seven men) volunteered for this investigation. Samples were drawn just before, immediately af ter and at 3 h, at 24h and at 48h after the race. Results Exercise ind uced a transient leucocytosis (P = 0.0002) and a mild acute-phase reac tion with increase in plasma C-reactive protein (CRP) (P = 0.0115) but nor in serum amyloid A (SAA) concentrations. Although plasma interleu kin 6 (IL-6) was undetectable and soluble interleukin-1 receptor type II (IL-1sRII) remained unchanged, interleukin-1 receptor antagonist (I L-1ra) concentrations were elevated directly after the race with a fur ther increase at 3h (P<0.0001). Soluble tumour necrosis factor (TNF) r eceptors were increased immediately after the run, but the effect was more marked for sTNFr p55 (twofold increase; P<0.0001) than for sTNFr p75 (1.16-fold increase; P=0.0007). In cell cultures, the LPS-induced release of the inflammatory cytokines doubled for IL-1 beta (P < 0.000 1) and for IL-1ra (P < 0.0001). In contrast, TNF-oc production decreas ed after the run, and a nadir was reached at 24h (P<0.0001). Conclusio n These results suggest that a 5-km run elicits both the production of acute-phase mediators (leucocytosis and elevation of CRP) and anti-in flammatory counter-regulation as judged by the increase in circulating concentrations of IL-1ra, sTNFr p55, and sTNFrp75 and down-regulation of LPS-stimulated TNF-a! production.