Increased concentrations of interleukin 1-β in whole blood cultures supernatants after 12 weeks of moderate endurance exercise

Abstract

The aim of the study was to investigate whether a regular moderate endurance exercise programme influenced the in vitro cytokine synthesis by stimulated whole blood cultures. To this end, eight healthy subjects exercised moderately by running for 3–5 h a week over a period of 12 weeks, whilst seven other healthy subjects served as the control group. The intensity of the exercise was determined by lactic acid concentrations in the blood which were maintained between 1.8 and 2.5 mmol · l⁻¹. Over the period of training the running velocity producing the 4 mmol · l⁻¹ lactic acid threshold increased from 2.86 (SD 0.83) m · s⁻¹ to 3.06 ± 0.79 m · s⁻¹ (P ≤ 0.008). Blood samples were taken at rest before and after the training programme. The following blood parameters were determined: leucocyte count, differential leucocyte count, lymphocyte subpopulations [CD14 positive (+)/CD45+, CD4+/CD25+, CD8+, CD16+/CD122+]. Whole blood cultures were stimulated with lipopolysaccarides [interleukin (IL)-1 β and IL-6] and staphylococcal enterotoxin B [IL-2, soluble interleukin 2 receptor (sIL2-R) and interferon (IFN)-γ]. Cytokine concentrations in the supernatants were measured using an enzyme-linked immunosorbent assay. The white blood cell count, differential leucocyte count, lymphocyte subset distribution and the expression of the CD25 and CD122 antigen on lymphocytes were unchanged by training. After the training programme the IL-1 β production changed significantly [1496 (SD 264) pg · ml⁻¹ before, compared to 2127 (SD 672) pg · ml⁻¹ after training, P ≤ 0.008]. In the control group these parameters remained unchanged. With respect to changes in the values in both groups the syntheses of IL-1 β (P ≤ 0.023) and IL-6 (P ≤ 0.021) were significantly higher after regular training. The syntheses of IL-2, sIL-2 and INF-γ were not significantly influenced. Regular endurance exercise influenced the in vitro production of monocyte derived cytokines, while the effect of exercise on the cytokines synthesized by T-cells appeared to be of lesser importance.