92
Views
0
CrossRef citations to date
0
Altmetric
Original Article

Thrombin-inducible platelet adhesion and regulation of the platelet seven-transmembrane thrombin receptor-1 (PAR-1): Effects of unfractionated heparin and lepirudin

, , & , MD
Pages 582-587 | Received 24 Jun 2009, Accepted 10 Aug 2009, Published online: 23 Nov 2009
 

Abstract

Heparin may induce platelet activation and even heparin-induced thrombocytopenia. Lepirudin has been approved for HIT treatment. We speculated that lepirudin inhibits platelet function under high shear and the platelet thrombin receptor PAR-1 better than heparin. Thrombin-inducible platelet adherence under high shear conditions and the expression of PAR-1 were studied after samples from healthy donors were exposed in vitro to increasing concentrations of unfractionated heparin or lepirudin. Compared to baseline and to lepirudin, heparin induced platelet P-selectin expression (p = 0.04). Platelet adherence increased slightly in the presence of lepirudin, but not heparin (p = 0.04). Thrombin-inducible platelet aggregate formation and consecutive adherence under high shear conditions was inhibited by both anticoagulants (p = 0.004). Further, heparin and lepirudin inhibited thrombin-inducible cleavage and internalization of PAR-1 at a dosage of 1.0 U/ml and 1.6 µg/ml, respectively (p = 0.004). Thus, heparin and lepirudin inhibit thrombin-inducible platelet activation in vitro to a similar extent.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.