title: Effects of exercise training and deconditioning on platelet aggregation induced by alternating shear stress in men.
abstract: OBJECTIVE
  Alternating shear stress, which resembles the flow condition in stenotic arteries, induces platelet aggregation. This study investigated how exercise training and deconditioning influence alternating shear-induced platelet aggregation (ASIPA) and clarify the mechanisms underlying ASIPA.
  
  
  RESULTS
  Thirty healthy male sedentary subjects were randomly divided into control and trained groups. The trained men were trained on a bicycle ergometer at approximately 60% of maximal oxygen consumption for 30 minutes per day, 5 days per week for 8 weeks, and then were deconditioned for 8 weeks. The experimental results indicate the following: (1) short-term strenuous exercise increases the extent of ASIPA and is accompanied by increased the von Willebrand factor (vWF) binding and P-selectin expression on platelets in both the control and trained groups, whereas the enhancement of platelet function decreases after exercise training in trained subjects; (2) at rest and immediately after exercise, ASIPA and the vWF binding and P-selectin expression on platelets are reduced by training, but remain unchanged in the control group; and (3) deconditioning reverses the effects of training on resting and postexercise state.
  
  
  CONCLUSIONS
  Exercise training suppresses the extent of ASIPA, probably by reducing vWF binding to platelets and P-selectin expression on platelets. However, deconditioning reverses the training effects. This investigation shows that exercise training decreases resting and severe exercise-promoted platelet aggregation induced by alternating shear stress (ASIPA); moreover, this effect is accompanied by reduced the von Willebrand factor binding and P-selectin expression on platelets. However, the effects of training on ASIPA are reversed to the pretraining state after deconditioning.
authors.affiliation: Graduate Institute of Rehabilitation Science, Center for Gerontological Research, Chang Gung University, Taoyuan, Taiwan. s5492@mail.cgu.edu.tw <s5492@mail.cgu.edu.tw>
authors.forename: Jong-Shyan
authors.initials: JS
authors.lastname: Wang
authors.forename: Yu-San
authors.initials: YS
authors.lastname: Li
authors.forename: Jin-Chung
authors.initials: JC
authors.lastname: Chen
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Chen
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000737:chemistry; D001794:Blood Pressure; D018493:Cardiovascular Deconditioning / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D018056:Hemorheology; D006801:Humans; D008297:Male; D009638:Norepinephrine / Q000097:blood; D010101:Oxygen Consumption; D019007:P-Selectin / Q000032:analysis; D010974:Platelet Aggregation / Q000502:physiology*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000032:analysis; D012146:Rest; D013314:Stress, Mechanical; D014841:von Willebrand Factor / Q000032:analysis
chemical_list: D019007:P-Selectin; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D014841:von Willebrand Factor; D009638:Norepinephrine