Plasminogen Platelet-activating factor

At. Akai, T., Niiya, K., Sakuragawa, N., lizuka, H., and Endo, S., Modulation of tissue-type plasminogen activator expression by platelet activating factor in human glioma cells. J. Neurooncol. 59, 193-198 (2002). 

Inhibits platelet aggregation by increasing levels of cAMP Binds protein C, which is then cleaved by thrombin to yield activated protein C this in combination with protein S degrades factors Va and Villa, limiting their actions Activates plasminogen to plas-min, which digests fibrin the action of t-PA is opposed by plasminogen activator inhibitor- (PAI-1)... 

Figure 22.5 (a) Injury to endothelial cells can lead to thrombosis. Healthy endothelial cells secrete two factors that inhibit thrombus formation (i) prostacyclins, which inhibit aggregation of platelets and (ii) a factor that facilitates conversion of plasminogen to plasmin. Injury to endothelial cells can facilitate thrombosis since (i) they do not secrete prostacyclins (ii) they do not secrete plasminogen activator and (iii) they secrete a factor that stimulates thrombosis. (b) Diagram of an atheroscle-rosed artery containing a thrombus. A thrombus is blocking the lumen of the artery that is not totally blocked by plaque. 

Inhibition of synthesis of prothrombin and coagulation factors Vll, IX, and X Inhibition of platelet aggregation in vitro Activation of plasminogen... 

Platelet aggregation different pathways of activation. Abbreviations ADR adenosine diphosphate ATP, adenosine triphosphate COX, cyclooxygenase PAI, plasminogen activator inhibitor PDGF, platelet derived growth factor. 

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