Thromb Haemost 1992; 68(01): 079-083
DOI: 10.1055/s-0038-1656322
Original Article
Schattauer GmbH Stuttgart

ADP Receptor Induced Activation of Guanine Nucleotide Binding Proteins in Rat Platelet Membranes– An Effect Selectively Blocked by the Thienopyridine Clopidogrel

Authors

  • C Gachet

    INSERM U.311, Centre Régional de Transfusion Sanguine, Strasbourg, France
  • P Savi

    1   Sanofi Recherche, Toulouse, France
  • P Ohlmann

    INSERM U.311, Centre Régional de Transfusion Sanguine, Strasbourg, France
  • J-P Maffrand

    1   Sanofi Recherche, Toulouse, France
  • K H Jakobs

    2   Pharmakologisches Institut, Universität Heidelberg, Heidelberg, FRG
  • J-P Cazenave

    INSERM U.311, Centre Régional de Transfusion Sanguine, Strasbourg, France
Weitere Informationen

Publikationsverlauf

Received 16. Juli 1991

Accepted after revision 13. Februar 1992

Publikationsdatum:
03. Juli 2018 (online)

Preview

Summary

The thienopyridine clopidogrel, a potent analog of ticlopidine, is a powerful inhibitor of ADP induced platelet aggregation and ADP induced inhibition of cyclic AMP accumulation in intact platelets but not of ADP induced shape change. We have recently demonstrated that ADP stimulates the binding of GTPγS to GTP binding proteins (G proteins) in human platelet membranes. We now studied the effects of clopidogrel, a specific inhibitor of ADP induced platelet aggregation on the stimulation of GTPγS binding to rat platelet membranes by ADP. Using the non hydrolyzable stable analog of ADP, 2MeSADP, we demonstrate that 2MeSADP stimulates the binding of [35S]GTPγS to rat platelet membranes in a concentration dependent manner, that this effect is inhibited by the specific ADP receptor antagonist Sp-ATPαS and that clopidogrel completely and selectively blocks the stimulation by 2MeSADP of [35S]GTPγS binding to platelet membranes of treated rats. We conclude that: i) rat platelet membranes possess an ADP receptor coupled to unidentified G protein(s) and ii) the thienopyridine clopidogrel impairs the interaction of the ADP receptor with its G protein by an irreversible modification the ADP receptor itself or its putative G protein.