Hypoxic exercise training affects Ox‐LDL‐stimulated thrombin generation of monocyte‐derived microparticles

Abstract

Thrombin activity is critical to determining the severity of haemostatic reactions. Oxidative‐low density lipoprotein (ox‐LDL) promotes the shedding of procoagulant‐rich microparticles from monocytes, thereby accelerating the pathogenesis of atherothrombosis. This study explicates the manner in which hypoxic exercise training affects monocyte‐derived microparticles (MDMP) release and MDMP‐mediated thrombin generation (TG) stimulated by ox‐LDL. Fifteen sedentary healthy men cycled on an ergometer at about 60% of maximal oxygen consumption under 15%O2 condition for 30 minutes per day, 5 days per week for 5 weeks. The MDMP characteristics and dynamic TG parameters were measured by two‐color flow cytometry and calibrated, automatic thrombinography, respectively. Our results showed that acute 12%O2 exercise increase levels of ox‐LDL‐induced releases of total, tissue factor‐rich, phosphatidylserine‐exposed MDMP, which were accompanied by elevated thrombin peak height and increased TG rate in MDMP‐rich plasma. However, 15%O2 exercise training for 5 weeks suppressed the enhancement of coagulant‐related MDMP release and MDMP‐mediated dynamic TG rate under ox‐LDL stimulation following acute 12%O2 exercise. Therefore, our results suggest that long‐term moderate‐intensity exercise at 15%O2 environment ameliorates the promotion of ox‐LDL‐induced TG of MDMP caused by acute 12%O2 exercise, which may in turn decrease the risk of athero‐thrombosis at performing extremely hypoxic exertion.