Shear-induced platelet aggregation is potentiated by desmopressin and inhibited by ticlopidine

Marco Cattaneo, Rossana Lombardi, Donato Bettega, Anna Lecchi, Pier Mannuccio Mannucci

Research output: Contribution to journalArticlepeer-review


Shear-induced platelet aggregation is important in physiological hemostasis and in the pathogenesis of arterial thrombosis. It requires extracellular Ca2+, platelet membrane glycoproteins Ib/IX and IIb/IIIa, von Willebrand factor (vWF), and ADP. We studied the effects of desmopressin (DDAVP), which increases plasma vWF levels and shortens the bleeding time, and of ticlopidine, which inhibits platelet responses to ADP, on shear-induced platelet aggregation. Eleven healthy volunteers were given oral ticlopidine (250 mg b.i.d.) for 7 days. The same subjects were infused intravenously with DDAVP (0.3 μg/kg body wt) before the first and after the last doses of ticlopidine. The degree of platelet aggregation induced by shear stress at 25, 50, 75, and 100 dyne/cm2 in a cone-and-plate viscometer, plasma vWF levels, and the bleeding time were measured before and after each DDAVP infusion. Plasma vWF levels and the extent of shear-induced platelet aggregation increased after DDAVP and were correlated. Ticlopidine partially inhibited shear-induced platelet aggregation both before and after DDAVP infusion. The bleeding time, prolonged by ticlopidine, was shortened by DDAVP. Potentiation by DDAVP of shear-induced platelet aggregation may be one mechanism by which the drug shortens the prolonged bleeding time. Since shear-induced platelet aggregation can cause thrombotic occlusions in stenotic arterial vessels, our findings may explain the therapeutic efficacy of ticlopidine in arterial thrombosis.

Original languageEnglish
Pages (from-to)393-397
Number of pages5
JournalArteriosclerosis, Thrombosis, and Vascular Biology
Issue number3
Publication statusPublished - 1993


  • ADP
  • Bleeding time
  • Desmopressin
  • Platelet aggregation
  • Shear stress
  • Ticlopidine
  • Von willebrand factor

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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