Platelet receptor integrin

In the intact blood vessel, ligands involved in adhesion to platelets, such as collagen, fibronectin, and von Willebrand factor, are sequestered in the subendothelium, thus preventing access to platelet adhesive receptors. Table 1 summarizes the functions of platelet membrane integrin receptors. 

Blockers/inhibitors of platelets receptors GP Ilb/IIIa (integrin allb(33) (abeiximab, tirofiban, eptifibatide) Prevent the link of fibrinogen with platelet receptors inhibiting platelet aggregation in front of different agonists... 

The glycoprotein (GP) Hb-IIIa receptor (integrin a fcbj) is expressed at high concentrations on the platelet surface, representing approximately 15% of the total surfece protein. 

The role of the platelet integrin GPIIb/IIIa receptor and its potential utility as a radio-diagnostic agent in the rapid detection of thromboembolic events has been demonstrated [6]. This approach may be useful for the noninvasive diagnosis of various thromboembolic disorders. 

Collagen is a major component of connective tissue that becomes exposed at the subendothelium of injured blood vessels. It contributes to platelet adhesion and also plays a role in platelet activation by binding to several receptors on platelets such as integrin a 2(3 1 or glycoprotein VI (GP VI). 

Integrins themselves are found on nearly all cells and mediate several physiological responses, such as cell-cell and cell-matrix interactions. Three families of integrins, each family with a common beta subunit in combination with distinct alpha subunits, have been recognized. The beta 1 family, also called very late lymphocyte-activation antigen or VLA, has receptors mediating extracellular matrix interactions with molecules such as collagen, laminin, and fibronectin. Naturally, platelets contain many of the receptors of the beta 1 family. 

---