Abstract
To investigate the underlying mechanisms of strenuous acute exercise-induced changes on platelet activation, eleven sedentary men received strenuous exercise on a bicycle ergometer. Blood samples were collected before and immediately after exercise. To specifically assess platelet adhesiveness on fibrinogen-coated surface in various experimental conditions, a tapered parallel-plate chamber that provided a range of shear stress covering the entire physiological range in human circulation was used. The assay of the number and affinity of α2-adrenergic sites on the platelet surface were carried by receptor binding assay. Furthermore, plasma catecholamine levels were measured by high performance liquid chromatography. Our results indicated that 1) platelet adhesiveness and plasma epinephrine/norepinephrine levels were increased by strenuous exercise; 2) the affinity of α2-adrenergic receptor on platelets decreased while the maximal binding number was significantly increased after strenuous exercise; 3) the synergetic effect of clonidine (α2-adrenergic agonist) to ADP-enhanced platelet adhesiveness on fibrinogen-coated surface was more pronouced after strenuous exercise than at rest. Therefore, we conclude that strenuous acute exercise enhances platelet adhesiveness possibly by altering the performance of platelet α2-adrenergic and fibrinogen receptors.
Original language | English |
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Pages (from-to) | A1041 |
Journal | FASEB Journal |
Volume | 12 |
Issue number | 5 |
State | Published - 20 03 1998 |