Chemokines are elevated in plasma after strenuous exercise in humans

During the last few years much attention has been paid to the chemokines. C hemokine receptors are necessary to render a target permissive for infectio n by the human immunodeficiency virus (HIV) and high concentrations of chem okines have been shown to protect against the progression of HIV disease to wards death. In the present study, we investigated the capability of strenu ous exercise to induce elevated plasma concentrations of the chemokines int erleukin (IL)-8, macrophage inflammatory protein (MIP)-1 alpha and MLP-1 be ta Eight male athletes completed the Copenhagen Marathon 1997. Blood was sa mpled before, immediately after the run and every 30 min during a 4 h recov ery period. Plasma chemokine concentrations were measured using enzyme-link ed immunosorbent assays. The IL-8, MIP-1 alpha and MTP-beta concentrations all peaked 0.5 h after the run when they were 6.7-fold, 3.5-fold and 4.1-fo ld increased, respectively. The elevated concentrations of chemokines in pl asma after exercise could have implications for HEV-infected individuals; a possibility that needs further investigation. infects target cells by inte racting with the cell surface protein CD4 and additional molecules, termed coreceptors, which have been identified as members of the chemokine recepto r family (Feng et al. 1996). Con-comitant expression of CD4 and a chemokine receptor is necessary to render a target eel susceptible to infection with HIV. Chemokines can prevent binding of HIV to the chemokine receptor by co mpetitive inhibition and it has been suggested that factors influencing the plasma concentrations of chemokines may therefore have the potential to af fect the progression of HIV disease (Zagury et al. 1998). We and others hav e previously shown that exercise induces production of the cytokines involv ed in inflammation, especially IL-6 and IL-1ra (Drenth et al. 1995; Nieman 1997; Ostrowski et al. 1998a, b, 1999). The present study investigated to w hat extent strenuous exercise affects the plasma concentrations of the chem okines interleukin (IL)-8, macrophage inflammatory protein (MIP)-1 alpha an d MTP-1 beta.