Platelets play a key role in atherosclerosis, thrombosis and acute coronary syndromes. Drugs that dissolve blood clot (thrombolytic agents) and that prevent clot propagation (antiplatelet and anticoagulant agents) are used to treat a broad array of cardiovascular diseases. Therapeutic manipulation of platelet function has focused principally on the use of aspirin which has proved effective in m...

Proteins that inhibit glycoprotein (GP) IIb/IIIa mediated platelet aggregation have been purified from the venom of two snake species. A small platelet aggregation inhibitor (p1.AI), multisquamatin (Mr = 5,700), was purified from Echis multisquamatus venom by hydrophobic interaction HPLC and two steps on C18 reverse phase HPLC. A larger p1.AI, contortrostatin (Mr = 15,000), was purified by a si...

Activation of the platelet glycoprotein (GP IIb/IIIa) receptor on the platelet surface is the final pathway of platelet aggregation, regardless of the initiating stimulus. Inhibitors of GP IIb/IIIa receptors include monoclonal antibodies (abciximab) against this receptor and peptidic and nonpeptidic synthetic specific receptor blockers. Abciximab exchanges between and binds to platelets for as ...

BACKGROUND Dosing of glycoprotein (GP) IIb/IIIa receptor antagonists is frequently based on the inhibition of platelet aggregation, which may be influenced by the agonist used or concurrent medications. Here we describe a monoclonal antibody-based technique to quantify total and ligand-occupied GPIIb/IIIa receptors. METHODS AND RESULTS In vitro binding of monoclonal antibodies, LYP18 (Mab1) a...

We studied the effects(s) of two monoclonal antibodies, 6D1 and 10E5 (directed against platelet glycoprotein Ib [GPIb] and the GPIIb/IIIa complex, respectively), and purified human plasma fibrinogen on the binding of released platelet-von Willebrand factor (vWf) to the platelet surface. Neither of the monoclonal antibodies nor fibrinogen had any effect on the amount of platelet-vWf expressed on...

INTRODUCTION Eptifibatide is a platelet glycoprotein IIb/IIIa (GP IIb/IIIa) receptor antagonist that inhibits fibrinogen binding to the activated GP IIb/IIIa site and prevents platelet-platelet interaction and clot formation. GP IIb/IIIa inhibitors improve outcome in patients undergoing percutaneous coronary intervention for acute coronary syndrome. Thrombocytopenia is a complication of GP IIb/...

The blockade of platelet integrin glycoprotein (GP) IIb/IIIa is a promising new antiplatelet strategy. The binding of ligands or of the ligand-mimetic peptide RGD causes a conformational change of GP IIb/IIIa from the nonactivated to the activated state. Because several blocking agents/inhibitors are ligand-mimetics, the current study evaluates whether these agents have the intrinsic property t...

The blockade of platelet integrin glycoprotein (GP) IIb/IIIa is a promising new antiplatelet strategy. The binding of ligands or of the ligand-mimetic peptide RGD causes a conformational change of GP IIb/IIIa from the nonactivated to the activated state. Because several blocking agents/inhibitors are ligand-mimetics, the current study evaluates whether these agents have the intrinsic property t...

Platelet aggregation plays a key role in the development of complications of atherosclerosis. By inhibiting platelet aggregation in a pharmacological way complications such as myocardial infarction and sudden death may be prevented. This goes for primary as well as secondary prevention. The most relevant substances for this goal are aspirin, clopidogrel and the new glycoprotein IIb/IIIa inhibit...

© 1999 Canadian Medical Association or its licensors Technology: Glycoprotein IIb/IIIa receptor antagonists of platelets Use: The activation of platelet glycoprotein IIb/IIIa receptors results in rapid thrombosis through specific binding of its ligand, fibrinogen. The use of the Fab fragment of the mouse/human chimeric monoclonal antibody 7E3, now known as the pharmaceutical abciximab (ReoPro),...