HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wiedmer, T. Articles by Sims, P. J. Search for Related Content PubMed PubMed Citation Articles by Wiedmer, T. Articles by Sims, P. J. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 261, Issue 31, 14587-14592, Nov, 1986

On the mechanism by which complement proteins C5b-9 increase platelet prothrombinase activity

T Wiedmer, CT Esmon and PJ Sims

Membrane assembly of complement proteins C5b-9 on human platelets results in a dose-dependent increase in the binding of coagulation factors Va and Xa to the plasma membrane, concomitant with a marked increase in platelet prothrombinase activity. Factor Va binding increased by 6-15-fold in platelets treated with the C5b-9 proteins as compared to controls. In the presence of near-saturating concentrations of factor Xa, factor Va binding to C5b-9-treated platelets approximately doubled. In the absence of added factor Va, C5b-9-treated platelets bound 1700 molecules of factor Xa versus 50 molecules/cell bound to controls, suggesting that C5b-9 assembly on the platelet surface initiates the release of platelet factor V from the alpha- granules. The capacity of the C5b-9 proteins to initiate the nonlytic release of the platelet alpha-granule storage pool was confirmed by assay for platelet factor 4. When measured in the presence of exogenous factor Va (2 micrograms/ml), factor Xa uptake by C5b-9 platelets increased to approximately 5500 molecules/cell (versus 330 molecules/cell for controls). Removal of external Ca2+ inhibited the C5b-9-initiated release of the alpha-granule storage pool and reduced by approximately 50% the expression of new factor Va binding sites, suggesting that these two events contributing to increased platelet prothrombinase activity are mediated in part by the influx of Ca2+ across the C5b-9 pore.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				I. del Conde, M. A. Cruz, H. Zhang, J. A. Lopez, and V. Afshar-Kharghan Platelet activation leads to activation and propagation of the complement system J. Exp. Med., March 21, 2005; 201(6): 871 - 879. [Abstract] [Full Text] [PDF]

				C. F. Mojcik and J. H. Levy Aprotinin and the systemic inflammatory response after cardiopulmonary bypass Ann. Thorac. Surg., February 1, 2001; 71(2): 745 - 754. [Abstract] [Full Text] [PDF]

				C. S. Rinder, H. M. Rinder, M. J. Smith, J. B. Tracey, J. Fitch, L. Li, S. A. Rollins, and B. R. Smith SELECTIVE BLOCKADE OF MEMBRANE ATTACK COMPLEX FORMATION DURING SIMULATED EXTRACORPOREAL CIRCULATION INHIBITS PLATELET BUT NOT LEUKOCYTE ACTIVATION J. Thorac. Cardiovasc. Surg., September 1, 1999; 118(3): 460 - 466. [Abstract] [Full Text] [PDF]

				M. Sawada, H. Yanamoto, I. Nagata, N. Hashimoto, I. Nakahara, Y. Akiyama, H. Kikuchi, and R. L. Macdonald Prevention of Neointimal Formation by a Serine Protease Inhibitor, FUT-175, After Carotid Balloon Injury in Rats • Editorial Comment Stroke, March 1, 1999; 30(3): 644 - 650. [Abstract] [Full Text] [PDF]

				P. M. Jansen, B. Eisele, I. W. de Jong, A. Chang, U. Delvos, F. B. Taylor Jr., and C. E. Hack Effect of C1 Inhibitor on Inflammatory and Physiologic Response Patterns in Primates Suffering from Lethal Septic Shock J. Immunol., January 1, 1998; 160(1): 475 - 484. [Abstract] [Full Text] [PDF]