Effect of Hypoxic Exercise Training on Thrombin Generation Modulated by Monocyte-derived Microparticles

• Main Authors: Ya Lun Chang, 張雅綸
• Other Authors: J. S. Wang
• Format: Others
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/33756480244677736592

碩士 === 長庚大學 === 物理治療學系 === 98 === Background and Purpose: 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. Pathological investigations have demonstrated that a hypercoagulable state contributes to increased risks of vascular thrombotic events in patients with episodic hypoxia, such as obstructive sleep apnea and chronic obstructive pulmonary disease. However, studies of the relationship between hypoxic exercise and monocyte-mediated thrombosis have not yet been investigated. This study explicates the manner in which hypoxic exercise training affects monocyte-derived microparticles (MDMP) release, MDMP binding coagulation factors―FV /FVIII, and MDMP-mediated thrombin generation (TG) stimulated by ox-LDL. Methods: Forty sedentary healthy men performed a acute hypoxic exercise test (60%VO2max for 30 min under 12%O2 in air) and trained a on a bicycle ergometer, engaging two groups: hypoxic exercise training group（60% VO2max under 15%O2 in air）and normoxic exercise training group（60% VO2max under ambient pressure）. Duration of training is 40 minutes per day including warm-up and cool-down, 5 days per week for 5weeks. At rest and immediately after acute hypoxic exercise, the MDMP characteristics, MDMP binding FV/FVIII and dynamic TG parameters were measured by two-color flow cytometry and calibrated, automatic thrombinography, respectively. Results: Both hypoxic exercise training and normoxic exercise training for 5 weeks improved subjects’ aerobic fitness at ventilation threshold and maximal performance by increasing their efficiency of pulmonary ventilation, but effects of hypoxic training is better than normoxic exercise training. That before the training, strenuous, acute 12% exercise increased levels of ox-LDL-induced releases of total, tissue factor-rich, phosphatidylserine-exposed MDMP and FV/FVIII binding MDMP, which were accompanied by elevated thrombin peak height and increased TG rate in MDMP-rich plasma. However, normoxic exercise training for 5 weeks suppressed the enhancement of coagulant-related MDMP release, MDMP-mediated dynamic TG rate and FV/FVIII binding levle under ox-LDL stimulation following acute 12%O2 exercise. Discussion: Our results suggest that long-term moderate-intensity exercise at environment ameliorates the promotion of ox-LDL-induced TG of MDMP and MDMP binding FV/FVIII caused by acute 12%O2 exercise. Clinical Relevance: These experimental findings provide a strategy of suitable exercise dose regimens that improve aerobic capacity by eliciting beneficial physiology changes.