Assessment of equine platelet aggregability and activation status: Methodological studies and the effect of exercise [microform]
- Bib ID:
- 3284288
- Format:
- Book and Microform
- Author:
- Kingston, Janene Kerrie
- Description:
- 155 p.
- ISBN:
- 049347739X
- Summary:
-
The objectives of this study were to evaluate: (1) the effect of different anticoagulants and exercise on measures of equine platelet aggregability and activation; (2) the usefulness of fluorescent-labeled annexin V, anti-thrombospondin, and anti-fibrinogen antibodies for measurement of equine platelet activation; and (3) the effect of formaldehyde on measures of equine platelet activation. Blood was collected from Thoroughbred horses at rest and during treadmill exercise. Platelet responses to four common platelet agonists, prostaglandin E1 (PGE1), and formaldehyde were evaluated following collection of blood in sodium citrate or low molecular weight heparin (LMWH). Platelet aggregation was assessed using optical aggregometry. Platelet activation was evaluated using flow cytometry, to detect binding of fluorescent-labeled annexin V, anti-human fibrinogen, and anti-human thrombospondin antibodies.
Determination of 14C-serotonin uptake and release was used to assess the extent of platelet secretion. Plasma concentration of ionized calcium was measured, using an ion-selective electrode. For samples collected into sodium citrate, the concentrations of sodium citrate and ionized calcium significantly affected platelet aggregability. Samples collected into LMWH during exercise showed significantly increased platelet aggregability, however LMWH resulted in platelet clumping and significantly lower platelet counts. Addition of PGE1 or sodium citrate to aggregated samples resulted in partial reversal of aggregation and fibrinogen binding. Binding of annexin V and anti-fibrinogen antibody were good measures of equine platelet activation, whereas anti-thrombospondin antibody binding was not. Formaldehyde fixation of platelets resulted in significant changes in anti-fibrinogen antibody and annexin V binding, with a gradual increase in fluorescence over time.
Exercise resulted in increased numbers of platelet-neutrophil aggregates, but there was no increase in binding of anti-fibrinogen antibody or annexin V. In conclusion, factors such as plasma sodium citrate concentration, the use of PGE1 or formaldehyde, and the choice of molecular markers, significantly influence measurement of equine platelet aggregability and activation. Improved methodologies are needed before the significance of increased numbers of platelet-neutrophil aggregates and platelet activation in association with exercise can be determined.
- Notes:
-
- (UnM)AAI3035216
- Source: Dissertation Abstracts International, Volume: 62-12, Section: B, page: 5583.
- Chair: Warwick M. Bayly.
- Thesis (Ph.D.)--Washington State University, 2001.
- Reproduction:
- Microfiche. Ann Arbor, Mich.: University Microfilms International.
- Subject:
- Biology, Veterinary Science
- Other authors/contributors:
- Washington State University
- Copyright:
-
In Copyright
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Copyright status was determined using the following information:
- Material type:
- Literary Dramatic Musical
- Published status:
- Unpublished
- Creation date:
- 2001
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