Summary

Heterotypic platelet-eosinophil/neutrophil aggregation and subsequentrelease of eosinophil/neutrophil oxidant products contributeto pathogenesis of conditions such as asthma and inflammatorybowel diseases.This study investigates whether warmupexercise (WUE) affects platelet-eosinophil/neutrophil interactionmediated by high-intensity exercise (HIE). Twenty-threehealthy sedentary men performed on three occasions light-intensityexercise (LIE, 40%VO_2max for 40 min) and HIE(80%VO_2max for 40 min) with and withoutWUE (40%VO_2max for20 min). Before and immediately after exercise, platelet-eosinophiland platelet-neutrophil aggregation (PEA and PNA), reactiveoxygen species production of eosinophils and neutrophils(EROS and NROS) enhanced by platelets, and adhesion moleculeexpression on platelets, eosinophils, and neutrophils weremeasured.The results of this study demonstrated that HIE enhancedPEA, PNA, and platelet-induced EROS and NROS, was accompanied by increased expressions of Mac-1 on eosinophilsand neutrophils and P-selectin on platelets at 5 dyne/cm2 ofshear stress, 100 µg/ml lipopolysaccharide, and 1 µM N-formylmethionyl-leucyl-phenylalanine treatments, whereas the enhancementof HIE on platelet-eosinophil/neutrophil interactionwas suppressed by WUE. Conversely, LIE significantly reducedPEA and PNA, suppressed platelet-induced EROS and NROS,and down-regulated eosinophil/neutrophil Mac-1 and plateletP-selectin expressions under various stimuli and shear flow conditions.Moreover, these effects were more pronounced in plateletinteraction with eosinophils than with neutrophils. It isconcluded that HIE enhances hetero-aggregation,adhesion moleculesexpressions, and subsequent oxidative bursts mediatedby platelets and eosinophils/neutrophils, this effect diminishesafter WUE. However, LIE minimizes the risk of thromboinflammation.