Platelet activity, sensitivity to agonist, and platelet--leukocyte conjugate formation after long-term exercise.
For rehabilitation training it is recommended that the intensity of exercise should be distinctly below the individual anaerobic threshold (IAT). We investigated platelet activity, reactivity and platelet-leukocyte conjugate formation following a stardardized treadmill (TR) ergometer test at 90% IAT for 60-120 min. Seventeen healthy male non-smokers underwent TR. Blood samples were taken after a 30-min rest, immediately after exercise, and 2 h after exercise completion. Platelets were detected flow cytometrically by CD41 in whole blood, activated platelets by CD62P. In addition, stimulation of platelets in vitro with 7.5 microM TRAP-6 was performed. For testing platelet-leukocyte conjugates, antibodies against CD45 and CD41 were used. After TR the percent of non-stimulated CD62P-positive platelets (%PC) remained unchanged (1.65 +/- 0.56 to 1.73 +/- 0.79%PC) (mean +/- SD). In contrast, an increase (P<0.05) from 31.9 +/- 13.5 to 37.4 +/- 15.0 %PC in CD62P, TRAP-6 stimulated and enhanced (P<0.01) platelet-leukocyte conjugates (11.7 +/- 3.7 to 16.1 +/- 6.9, CD41-%PC) after TR were observed. Both changes were independent of thrombin generation measured by F1+2 and TAT, and reversible after 2 h. Long-term exercise (90% IAT) on a treadmill ergometer only leads to a moderate increase of platelet reactivity and platelet-leukocyte conjugates. The determination of platelet-leukocyte conjugates may offer the possibility to detect an early activation stage of platelets in vivo.
Department of Sports Medicine, Friedrich-Schiller-University Jena, Jena, Germany. t.hilberg@ghz.de
Thomas
T
Hilberg
Volker
V
Schmidt
Doreen
D
Gläser
Dominik
D
Schammne
Wolfgang
W
Lösche
Holger H W
HH
Gabriel
D000328:Adult; D000990:Antithrombin III; D015415:Biomarkers / Q000097:blood; D001772:Blood Cell Count; D001792:Blood Platelets / Q000166:cytology*; D002448:Cell Adhesion; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007962:Leukocytes / Q000166:cytology*; D008297:Male; D010446:Peptide Fragments / Q000097:blood; D010447:Peptide Hydrolases / Q000097:blood; D015539:Platelet Activation; D011516:Prothrombin; D013178:Sports Medicine
D015415:Biomarkers; D010446:Peptide Fragments; C046193:antithrombin III-protease complex; C045879:prothrombin fragment 1.2; D000990:Antithrombin III; D011516:Prothrombin; D010447:Peptide Hydrolases