spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

Right arrow Help viewing high resolution images
Right arrow Return to article
(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.



Fig. 1. Stages in the development of a platelet thrombus on collagen exposed at sites of injury. The initial interaction of platelets with subendothelial collagens under high shear conditions present in the arterial circulation is indirectly mediated by von Willebrand factor, which binds collagen and platelet GPIb. This unstable interaction facilitates transient tethering and rolling. GPIb-mediated adhesion is superseded by more-stable binding to collagen by GPVI and integrin {alpha}2ß1. This, together with GPIb, stimulates platelet signalling that results in shape change and spreading, and the secretion and release of multiple prothrombotic factors. Integrin affinity becomes upregulated through inside-out signalling, resulting in fibrinogen-mediated platelet aggregation through binding to integrin {alpha}IIbß3, and adhesion is stabilized by enhanced binding of collagen and von Willebrand factor to integrins {alpha}2ß1 and {alpha}IIbß3, respectively.





Right arrow Return to article