Annexin V binding to platelets is agonist, time and temperature dependent
2010 (English)In: Platelets, ISSN 0953-7104, E-ISSN 1369-1635, Vol. 21, no 4, 289-296 p.Article in journal (Refereed) Published
Platelets bind annexin V when stimulated with combinations of platelet agonists such as collagen and thrombin. Previous studies have demonstrated significant heterogeneity of platelets binding annexin V. The relative role of the thrombin protease-activated receptors (PARs), PAR1 and PAR4, together with different methods of platelet preparation on annexin V binding to platelets is unclear. We therefore investigated the role of PAR1- and PAR4-activating peptides in combination with collagen-related peptide on annexin V binding. In diluted whole blood, PAR1- and PAR4-activating peptides were as effective as thrombin in inducing annexin V binding. However, in washed platelets, PAR-activating peptides were less potent than thrombin at inducing annexin V binding. This difference was more pronounced when experiments were performed at 37 degrees C compared to room temperature. In studies of diluted whole blood, platelet rich plasma and washed platelets, platelets incubated at room temperature bound more annexin V than platelets incubated at 37 degrees C. We also saw a significant effect of time on annexin V binding, in that more annexin V bound to platelets with longer incubation times. In conclusion, PAR1 and PAR4-activating peptides were as effective as thrombin in inducing annexin V binding in combination with collagen-related peptide in diluted whole blood and platelet rich plasma, but not in washed platelets. In addition, incubation temperature and time has a strong influence on annexin V binding to platelets. Thus variations in these conditions may explain the differences observed between previous studies.
Place, publisher, year, edition, pages
2010. Vol. 21, no 4, 289-296 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-71575DOI: 10.3109/09537101003660564PubMedID: 20230207OAI: oai:DiVA.org:liu-71575DiVA: diva2:450715