What does GPIIb IIIa receptor bind to?
Activated GPIIb-IIIa binds fibrinogen or von Willebrand factor, which forms molecular bridges between aggregating platelets.
What activates GPIIb IIIa?
Shear-induced activation of the GPIIb/IIIa is initiated by the interaction of GPIbα with VWF immobilized to the exposed subendothelium of the injured vessel wall, especially in the atherosclerotic plaque rupture, leading to platelet-surface adhesion.
Which of the following drugs is an inhibitor of platelet glycoprotein IIb IIIa receptors*?
Eptifibatide (Integrilin) is an antagonist of the platelet GP IIb/IIIa receptor; it reversibly prevents von Willebrand factor, fibrinogen, and other adhesion ligands from binding to the GP IIb/IIIa receptor. The end effect is the inhibition of platelet aggregation.
Why do GPIIb IIIa inhibitors cause thrombocytopenia?
Blood (2003) 101 (1): 1. The GPIIb/IIIa antagonists are a new and promising class of antithrombotic agents that bind specifically to GPIIb/IIIa (αIIbβ3 integrin), inhibit its interaction with fibrinogen, and prevent platelet aggregation.
What is the role of glycoprotein IIb IIIa receptor inhibitors in the acute care setting?
Glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitors prevent platelet aggregation by blocking glycoprotein IIb/IIIa receptors; thus, they found application in the management of coronary artery disease (CAD). The available GP IIb/IIIa inhibitors include abciximab, tirofiban, and eptifibatide.
What chemical activates platelets?
Platelet activation begins seconds after adhesion occurs. It is triggered when collagen from the subendothelium binds with its receptors (GPVI receptor and integrin α2β1) on the platelet.
What prevents activation of platelets?
Dipyridamole inhibits platelet activation through inhibition of platelet phosphodiesterase activity, ultimately blocking calcium-mediated platelet activation. Ticlopidine and clopidogrel inhibit the excitatory receptor P2Y1, thereby blocking adenosine diphosphate–induced platelet aggregation.
Does collagen activate platelets?
In addition, in normal wound healing, collagen is often the initial activator of platelets, with a platelet monolayer forming over the exposed collagen. Once the initial platelet layer is formed, there is a secondary accumulation of additional platelets via the action of thrombin.
What causes platelets to become activated?
Platelets are normally activated in the presence of tissue injury with endothelial disruption and loss of activation inhibitors, exposure of the von Willebrand factor that binds it’s receptor and slows circulating platelets, and release of ADP, thrombin, and TxA2 as well as binding of fibrinogen or collagen to αIIb/β3.
What happens if P-glycoprotein is inhibited?
Drug absorption Like the enzymes involved in drug metabolism, substrates of P-glycoprotein can potentially act as inhibitors or inducers of its function. Inhibition of P-glycoprotein can result in increased bioavailability of the susceptible drug. Induction of P-glycoprotein reduces the bioavailability.
What is the function of the GPIIb/IIIa receptor?
The gpIIb/IIIa receptor is a target of several drugs including abciximab, eptifibatide, and tirofiban . Once platelets are activated, granules secrete clotting mediators, including both ADP and TXA2. These then bind their respective receptors on platelet surfaces, in both an autocrine and paracrine fashion (binds both itself and other platelets).
What is the GPIIb/IIIa Odyssey?
The GPIIb/IIIa (integrin αIIbβ3) odyssey: a technology-driven saga of a receptor with twists, turns, and even a bend. 1Laboratory of Blood and Vascular Biology, The Rockefeller University, New York, NY; and. 2Department of Medicine, University of California, San Diego, La Jolla. Corresponding author.
What is the mechanism of action of GP IIb/IIIa inhibitors?
Taking advantage of the distinct mechanisms of activation and aggregation, the GP IIb/IIIa inhibitors interfere with platelet activity at the final common pathway of platelet-induced thrombosis.
What is the function of glycoprotein IIb/IIIa?
In medicine, glycoprotein IIb/IIIa ( GPIIb/IIIa, also known as integrin αIIbβ3) is an integrin complex found on platelets. It is a receptor for fibrinogen and von Willebrand factor and aids platelet activation.