title: Absolute hypoxic exercise training enhances in vitro thrombin generation by increasing procoagulant platelet-derived microparticles under high shear stress in sedentary men.
abstract: HS (high shear) stress associated with artery stenosis facilitates TG (thrombin generation) by increasing the release of procoagulant PDMPs (platelet-derived microparticles). Physical exercise and hypoxia may paradoxically modulate vascular thrombotic risks. The aim of the present study was to investigate how exercise training with/without hypoxia affected TG mediated by PDMPs under physio-pathological shear flows. A total of 75 sedentary males were randomly divided into five groups (n=15 in each group): 21% O2 [NC (normoxic control)] or 15% O2 [HC (hypoxic control)] at rest or were trained at 50% of peak work rate under 21% O2 [NT (normoxic training)] or 15% O2 [HAT (hypoxic-absolute training)], or 50% of HR (heart rate) reserve under 15% O2 [HRT (hypoxic-relative training)] for 30 min/day, 5 days/week for 4 weeks. The PDMP characteristics and dynamic TG were measured by flow cytometry and thrombinography respectively. Before the intervention, strenuous exercise markedly increased the PDMP count (14.8%) and TG rate (19.5%) in PDMP-rich plasma at 100 dynes/cm2 of shear stress (P<0.05). After the interventions, both NT and HRT significantly attenuated the enhancement of HS-induced PDMPs (4.7 and 4.9%) and TG rate (3.8 and 3.0%) (P<0.05) by severe exercise. Conversely, HAT notably promoted the PDMP count (37.3%) and TG rate (38.9%) induced by HS (P<0.05), concurrent with increasing plasma TF (tissue factor) and coagulation factor V levels at rest or following exercise. We conclude that both HRT and NT depress similarly HS-mediated TG during exercise, but HAT accelerates the prothrombotic response to vigorous exercise. These findings provide new insights into how exercise training under a hypoxic condition influences the risk of thrombosis associated with stenotic arteries.
authors.affiliation: Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Chen
authors.forename: Yi-Ching
authors.initials: YC
authors.lastname: Chen
authors.forename: Jong-Shyan
authors.initials: JS
authors.lastname: Wang
mesh_terms: D001779:Blood Coagulation Factors / Q000378:metabolism; D001792:Blood Platelets / Q000378:metabolism; D001809:Blood Viscosity / Q000502:physiology; D055252:Cell-Derived Microparticles / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D013314:Stress, Mechanical; D013917:Thrombin / Q000096:biosynthesis*; D055815:Young Adult
chemical_list: D001779:Blood Coagulation Factors; D013917:Thrombin