ENDOTHELIUM - ROLES IN THROMBOSIS AND HEMOSTASIS

  • 1 January 1977
    • journal article
    • research article
    • Vol. 101  (2) , 61-63
Abstract
The renewed interest in endothelial function is based partly on success with tissue culture of endothelial cells. Bovine and human endothelium functions primarily in the control of blood vessel wall permeability and in the provision of a blood-compatible lining surface. Endothelial cells may be active metabolically in ways that may help prevent thrombosis. Endothelium actively degrades several different vasoactive compounds that circulate in blood and can serve as platelet-aggregating agents. Endothelium contains an inhibitor of platelet function and an activator of plasminogen, both of which can be released from the cell in response to appropriate stimuli. While intact endothelium functions primarily in prevention of thrombosis, damaged endothelium can contribute greatly to thrombus formation. Release of prostaglandins, adenine nucleotides and other intracellular components from damaged endothelium can enhance platelet aggregation. Damaged endothelium may not function effectively in removal of vasoactive agents and may not release effective quantities of the inhibitor of platelet function or the activator of plasminogen. Altered endothelium exhibits tissue-factor activity, which can activate the extrinsic blood coagulation-system cascade. Altered endothelial cells may contract and expose basement membrane to blood, thus enhancing thrombosis.