Despite the success of abciximab in preventing ischemic events after percutaneous coronary interventions, attempts to develop intravenous, small-molecule glycoprotein IIb/IIIa antagonists and diversify the clinical indications for these agents have produced varied results. The 30-day ischemic event reduction in the percutaneous coronary intervention trials has ranged by over three-fold (16% to ...

OBJECTIVE To study the effect of unfractionated heparin (UFH) versus low molecular weight heparin (LMWH) in combination with glycoprotein (Gp) IIb/IIIa blockers on platelet activation and aggregation. METHODS Washed platelets were stimulated with thrombin in the presence or absence of UFH (monoparin), LMWH (enoxaparin), and a Gp IIb/IIIa blocker (abciximab, eptifibatide, or tirofiban). RESU...

The glycoprotein (GP) IIb-IIIa complex was isolated from human platelet membranes by immunoaffinity chromatography using a monoclonal antibody specific for GP IIb-IIIa. GP IIb and IIIa were further separated in the presence of sodium dodecyl sulfate (SDS) by gel filtration high-performance liquid chromatography (HPLC). Two cycles of this procedure yielded almost complete separation of homogeneo...

The biochemical details of the platelet surface as they relate to normal platelet function have been elucidated through study of labeled membranes from both normal platelets and those with congenitially defective function. Several cytoadhesive glycoprotein complexes which are integral components of the platelet membrane have been demonstrated to act as important receptors for extracellular matr...

Platelet glycoprotein (GP) IIb-IIIa inhibitors may become useful antithrombotic agents. Ro 43-5054 is a low molecular weight, noncyclic, peptidomimetic inhibitor that is three orders of magnitude more potent than RGDS in inhibiting fibrinogen binding to purified GPIIb-IIIa and in preventing platelet aggregation. Comparisons of RGDS and Ro 43-5054 in cell adhesion assays showed that, in contrast...

The central role of platelets in acute coronary syndromes (ACS) and percutaneous coronary interventions (PCI) is well appreciated. The various platelet activation mechanisms finally lead to the expression and activation of surface glycoprotein IIb/ IIIa receptors that mediate platelet aggregation and thrombus formation. Glycoprotein IIb/IIIa inhibitors (GPIs) are the most potent antiplatelet ag...

The interaction of fibrinogen with monocytes was studied. After stimulation with ADP (10 microM) or thrombin (1 U/ml), platelet-free suspensions of human monocytes bind 125I-fibrinogen with two different affinities in a specific and Ca2+-dependent reaction with saturation at 5.80-7.35 X 10(-7) M of added protein. The binding of fibrinogen to specific receptors on monocytes induces the procoagul...