Localization of thrombospondin in clots formed in situ.

摘要: Thrombospondin is a principal glycoprotein secreted by thrombin- stimulated platelets and has known affinities for fibrinogen fibrin. We studied the distribution of thrombospondin in clots formed situ on Formvar-coated coverslips at 37 degrees C intervals up to 17 hours. The distributions three other major platelet granular proteins--fibrinogen, fibronectin, von Willebrand factor (vWF)-- were also determined. portions adhering after stripping, washing, fixation with formaldehyde stained four proteins peroxidase-antiperoxidase technique. Monoclonal antibodies used localize thrombospondin, vWF; affinity-purified polyclonal fibrinogen. Platelets positively all proteins. was maximally present fibrin meshwork from 1 1/2 2 hours, which intensity staining decreased until only trace amounts detectable between Antifibrinogen and, lesser extent, antifibronectin time points. vWF not any point. Staining polymorphonuclear leukocytes (PMNLs) fine pattern found antithrombospondin. fraction PMNLs 6% 14% 4 hours increased eight 27%. At 52% thrombospondin. More than 48% antifibrinogen did stain either fibronectin or vWF. These studies indicate that transient component temporary unique spatial temporal hemostatic plug.