Evaluation of binding of fibrinogen and annexin V to equine platelets in response to supramaximal treadmill exercise.
There is evidence that equine platelet reactivity is altered by strenuous exercise. Changes in platelet reactivity could impact haemostasis following exercise-induced injury and may play a role in the pathophysiology of exercise-induced pulmonary haemorrhage. Interpretation of results of previous studies is hindered by potential in vitro-induced changes in platelet activity through the choice of anticoagulant and the use of platelet inhibitors. The present study was undertaken to re-evaluate the effect of exercise on equine platelets using methodologies that minimise in vitro-induced changes in platelet activation. The percentage of platelet-neutrophil aggregates increased significantly (P = 0.01) from mean +/- s.e. 3.5 +/- 0.6% at rest to 7.2 +/- 13% during exercise. There were no significant changes in binding of anti-fibrinogen antibody or annexin V to platelets in response to exercise. An inability to detect increased binding of fibrinogen or annexin V may be a result of poor test sensitivity or low statistical power. Alternatively, activated platelets may be quickly removed from the circulation and miss detection. The significance of increased numbers of platelet-neutrophil aggregates in association with exercise is currently unknown and warrants further investigation.
Kingston
J K
JK
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman 99164-6610, USA.
Bayly
W M
WM
Meyers
K M
KM
Sellon
D C
DC
Wardrop
K J
KJ
D000818:Animals; D017304:Annexin A5 / Q000276:immunology / Q000378:metabolism*; D000906:Antibodies / Q000097:blood; D001792:Blood Platelets / Q000378:metabolism*; D005080:Exercise Test / Q000662:veterinary; D005340:Fibrinogen / Q000276:immunology / Q000378:metabolism*; D005434:Flow Cytometry; D006470:Hemorrhage / Q000209:etiology / Q000503:physiopathology / Q000662:veterinary; D006734:Horse Diseases / Q000209:etiology / Q000503:physiopathology; D006736:Horses / Q000097:blood / Q000502:physiology*; D008171:Lung Diseases / Q000209:etiology / Q000503:physiopathology / Q000662:veterinary; D009504:Neutrophils; D010805:Physical Conditioning, Animal / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D015539:Platelet Activation / Q000502:physiology*; D010974:Platelet Aggregation / Q000502:physiology
D017304:Annexin A5; D000906:Antibodies; D005340:Fibrinogen