Cell-derived procoagulant microparticles (MP) might be able to contribute to exercise-induced changes in blood hemostasis.
This study aimed to examine (i) the concentration and procoagulant activity of cell-derived MP after a moderate endurance exercise and (ii) the differences in the release, clearance, and activity of MP before and after exercise between trained and untrained individuals.
All subjects performed a single bout of physical exercise on a bicycle ergometer for 90 min at 80% of their individual anaerobic threshold. MP were identified and quantified by flow cytometry measurements. Procoagulant activity of MP was measured by a prothrombinase activity assay as well as tissue factor-induced fibrin formation in MP-containing plasma.
At baseline, no differences were observed for the absolute number and procoagulant activities of MP between trained and untrained subjects. However, trained individuals had a lower number of tissue factor-positive monocyte-derived MP compared with untrained individuals. In trained subjects, exercise induced a significant increase in the number of MP derived from platelets, monocytes, and endothelial cells, with maximum values at 45 min after exercise and returned to basal levels at 2 h after exercise. Untrained subjects revealed a similar increase in platelet-derived MP, but their level was still increased at 2 h after exercise, indicating a reduced clearance compared with trained individuals. Procoagulant activities of MP were increased immediately after exercise and remained elevated up to 2 h after exercise.
We conclude that increased levels of MP were found in healthy individuals after an acute bout of exercise, that the amount of circulating MP contributes to an exercise-induced increase of hemostatic potential, and that there were differences in kinetic and dynamic characteristics between trained and untrained individuals.
1Department of Anaesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, GERMANY; and 2Department of Sports Medicine, Institute of Sports Science, Jena Friedrich-Schiller University, Jena, GERMANY
Address for correspondence: Maik Sossdorf, Ph.D., Department of Anaesthesiology and Intensive Care, Jena University Hospital, Erlanger Allee 101, D-07740 Jena, Germany; E-mail: email@example.com.
Submitted for publication August 2010.
Accepted for publication November 2010.