Procoagulant factors

The procoagulant factors produced by endothelial cells are the coagulation factors von Willebrand factor (WF), F-V, F-VIII, tissue factor (TF), and plasminogen activator inhibitor (PAI), which blocks the activators u-PA and t-PA and counteracts fibrinolysis (G21, FI6). It has been shown that under the influence of complement activation (C9), in response to endotoxin in vitro (C24), in experimental E. coli sepsis in baboons (D30), and after stimulation with TNF (Al, N6), endothelial cells up-regulate the expression of TF, down-regulate TM and inhibit the production of t-PA and PAF. Thus, the balance may shift in the procoagulant direction with a large excess of PAI-1. 

Widespread e.g. Vaccinium corymbosum (Ericaceae), Medicago saliva (alfalfa) (Fabaceae), Castaneasp. (chestnut) (Fagaceae) [leaf]), Triticum aestivum (Poaceae) Dihydro form (KH ) coenzyme for "y-carboxyglutamic acid formation on procoagulant factors II, VII, IX X, anticoagulant proteins C S, matrix Gla protein osteocalcin... 

Activated protein C in conjunction with its cofactor, protein S, plays a key role in the anticoagulant system by inactivating membrane-bound factors Va and Villa, The inability to inactivate procoagulant factors Va or Villa could disturb hemostasis, heighten the coagulation pathway, increase the generation of thrombin, and promote clot formation. In 1993 Dahlback reported familial thrombophilia caused by resistance to activated protein C (APC). In 1994... 

Determination of possible cause of increased bleeding tendency in the absence of procoagulant factor deficiency, performed only in specialized laboratories... 

Activation ofV receptors by desmopressin or vasopressin increases circulating levels of procoagulant factor VIII and von Willebrand factor These effects are mediated by extrarenal V receptors. Presumably, vasopressin stimulates the secretion of von Willebrand factor and of factor VIII from storage sites in vascular endothelium. Since release of von Willebrand factor does not occur when desmopressin is applied directly to cultured endothelial cells or to isolated blood vessels, intermediate factors are likely to be involved. 

---