Platelet-activating factor and not thromboxane A2 is an important mediator of endotoxin-induced platelet aggregation in equine heparinised whole blood in vitro.
Abstract: Endotoxin has previously been shown to induce platelet aggregation in equine heparinised whole blood. This study aimed to determine whether platelet-activating factor or products of cyclo-oxygenase metabolism (thromboxane A2 or prostaglandins) were important in mediating the response of platelets to endotoxin. The effects of the following drugs on endotoxin-induced aggregation were investigated: aspirin, flunixin meglumine and carprofen (non-steroidal anti-inflammatory drugs); CV-3988 and WEB2086 (platelet-activating factor receptor antagonists); quinacrine (phospholipase A2 inhibitor). The effects of quinacrine on platelet aggregation in citrated platelet-rich plasma induced by ADP and platelet-activating factor were also investigated. CV-3988 and WEB2086 caused a concentration-dependent inhibition of endotoxin-induced aggregation. The non-steroidal anti-inflammatories were without effect except flunixin meglumine which produced a small inhibition of endotoxin-induced aggregation. Quinacrine had a similar effect to the platelet-activating factor antagonists, but also non-competitively inhibited platelet aggregation in citrated platelet-rich plasma. It is concluded that platelet-activating factor is a critical mediator of endotoxin-induced platelet aggregation in the horse, but that products of cyclo-oxygenase metabolism are not of importance.
Publication Date: 1996-03-01 PubMed ID: 8735817DOI: 10.1097/00001721-199603000-00021Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research article explores the role of platelet-activating factor in endotoxin-induced platelet aggregation in horse blood, concluding that it is of critical importance, while cyclo-oxygenase metabolism products are not.
Objective of the Study
- This study was performed to analyze the roles of platelet-activating factor and the by-products of cyclo-oxygenase metabolism (thromboxane A2 or prostaglandins) in mediating the effect of endotoxin on platelet aggregation in equine heparinised whole blood.
Method Used
- The researchers investigated the effects of various drugs on endotoxin-induced aggregation. These drugs include aspirin, flunixin meglumine, and carprofen (all of which are non-steroidal anti-inflammatory drugs), CV-3988 and WEB2086 (both are platelet-activating factor receptor antagonists), and quinacrine (a phospholipase A2 inhibitor).
- The team also examined the effects of quinacrine on platelet aggregation in citrated platelet-rich plasma caused by ADP and platelet-activating factor.
Key Findings
- The study identified that CV-3988 and WEB2086 caused a concentration-dependent inhibition of endotoxin-induced aggregation.
- The non-steroidal anti-inflammatory drugs did not have any significant effect on endotoxin-induced aggregation, except for flunixin meglumine, which showed slight inhibition.
- Quinacrine not only demonstrated similar effects to the platelet-activating factor antagonists, but also inhibited platelet aggregation in citrated platelet-rich plasma non-competitively.
Conclusion
- The study concluded that the platelet-activating factor plays a vital role in endotoxin-induced platelet aggregation in horse blood.
- However, the role of the by-products of cyclo-oxygenase metabolism in the same process was deemed not significant.
Cite This Article
APA
Jarvis GE, Evans RJ.
(1996).
Platelet-activating factor and not thromboxane A2 is an important mediator of endotoxin-induced platelet aggregation in equine heparinised whole blood in vitro.
Blood Coagul Fibrinolysis, 7(2), 194-198.
https://doi.org/10.1097/00001721-199603000-00021 Publication
Researcher Affiliations
- Department of Clinical Veterinary Medicine, University of Cambridge, UK.
MeSH Terms
- Animals
- Anti-Inflammatory Agents, Non-Steroidal / pharmacology
- Aspirin / pharmacology
- Azepines / pharmacology
- Carbazoles / pharmacology
- Clonixin / analogs & derivatives
- Clonixin / pharmacology
- Endotoxins / pharmacology
- Heparin
- Horses
- In Vitro Techniques
- Phospholipases A / antagonists & inhibitors
- Phospholipases A2
- Phospholipid Ethers / pharmacology
- Platelet Activating Factor / metabolism
- Platelet Aggregation / drug effects
- Platelet Aggregation Inhibitors / pharmacology
- Quinacrine / pharmacology
- Thromboxane A2 / metabolism
- Triazoles / pharmacology
Citations
This article has been cited 1 times.- Goulding DR, Myers PH, Goulding EH, Blankenship TL, Grant MF, Forsythe DB. The effects of perioperative analgesia on litter size in Crl:CD1(ICR) mice undergoing embryo transfer. J Am Assoc Lab Anim Sci 2010 Jul;49(4):423-6.
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