Chemokines are elevated in plasma after strenuous exercise in humans

During the last few years much attention has been paid to the chemokines. Chemokine receptors are necessary to render a target permissive for infection by the human immunodeficiency virus (HIV) and high concentrations of chemokines have been shown to protect against the progression of HIV disease towards death. In the present study, we investigated the capability of strenuous exercise to induce elevated plasma concentrations of the chemokines interleukin (IL)-8, macrophage inflammatory protein (MIP)-1 alpha and MLP-1 beta Eight male athletes completed the Copenhagen Marathon 1997. Blood was sampled before, immediately after the run and every 30 min during a 4 h recovery period. Plasma chemokine concentrations were measured using enzyme-linked 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-fold increased, respectively. The elevated concentrations of chemokines in plasma after exercise could have implications for HEV-infected individuals; a possibility that needs further investigation. infects target cells by interacting with the cell surface protein CD4 and additional molecules, termed coreceptors, which have been identified as members of the chemokine receptor 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 competitive inhibition and it has been suggested that factors influencing the plasma concentrations of chemokines may therefore have the potential to affect the progression of HIV disease (Zagury et al. 1998). We and others have previously shown that exercise induces production of the cytokines involved 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 what extent strenuous exercise affects the plasma concentrations of the chemokines interleukin (IL)-8, macrophage inflammatory protein (MIP)-1 alpha and MTP-1 beta.