title: Interval and continuous exercise regimens suppress neutrophil-derived microparticle formation and neutrophil-promoted thrombin generation under hypoxic stress.
abstract: Acute hypoxic exposure increases vascular thrombotic risk. The release of procoagulant-rich microparticles from neutrophils accelerates the pathogenesis of inflammatory thrombosis. The present study explicates the manner in which interval and continuous exercise regimens affect neutrophil-derived microparticle (NDMP) formation and neutrophil/NDMP-mediated thrombin generation (TG) under hypoxic condition. A total of 60 sedentary males were randomized to perform either aerobic interval training [AIT; 3-min intervals at 40% and 80% V̇O2max (maximal O2 consumption)] or moderate continuous training (MCT; sustained 60% V̇O2max) for 30 min/day, 5 days/week for 5 weeks, or to a control (CTL) group who did not receive any form of training. At rest and immediately after hypoxic exercise test (HE, 100 W under 12% O2 for 30 min), the NDMP characteristics and dynamic TG were measured by flow cytometry and thrombinography respectively. Before the intervention, HE (i) elevated coagulant factor VIII/fibrinogen concentrations and shortened activated partial thromboplastin time (aPTT), (ii) increased total and tissue factor (TF)-rich/phosphatidylserine (PS)-exposed NDMP counts and (iii) enhanced the peak height and rate of TG promoted by neutrophils/NDMPs. Following the 5-week intervention, AIT exhibited higher enhancement of V̇O2max than did MCT. Notably, both MCT and AIT attenuated the extents of HE-induced coagulant factor VIII/fibrinogen elevations and aPTT shortening. Furthermore, the two exercise regimens significantly decreased TF-rich/PS-exposed NDMP formation and depressed neutrophil/NDMP-mediated dynamic TG at rest and following HE. Hence, we conclude that AIT is superior to MCT for enhancing aerobic capacity. Moreover, either AIT or MCT effectively ameliorates neutrophil/NDMP-promoted TG by down-regulating expression of procoagulant factors during HE, which may reduce thrombotic risk evoked by hypoxia. Moreover, either AIT or MCT effectively ameliorates neutrophil/NDMP-promoted TG by down-regulating expression of procoagulant factors during HE, which may reduce thrombotic risk evoked by hypoxia.
authors.affiliation: *Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Medical Collage, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Yi-Ching
authors.initials: YC
authors.lastname: Chen
authors.affiliation: *Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Medical Collage, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Ching-Wen
authors.initials: CW
authors.lastname: Ho
authors.affiliation: *Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Medical Collage, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Hsing-Hua
authors.initials: HH
authors.lastname: Tsai
authors.affiliation: *Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Medical Collage, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Jong-Shyan
authors.initials: JS
authors.lastname: Wang
mesh_terms: D000704:Analysis of Variance; D001772:Blood Cell Count; D001777:Blood Coagulation / Q000502:physiology; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000503:physiopathology*; D008297:Male; D009504:Neutrophils / Q000378:metabolism*; D012307:Risk Factors; D057185:Sedentary Behavior; D013312:Stress, Physiological / Q000502:physiology; D013917:Thrombin / Q000378:metabolism*; D013927:Thrombosis / Q000097:blood / Q000503:physiopathology; D013997:Time Factors; D055815:Young Adult
chemical_list: D013917:Thrombin