Reactome: A Curated Pathway Database
Attention
The EBI data centre will be shutting down from the afternoon (BST) of Friday 26th August until the afternoon of Tuesday 30th August 2016 for essential maintenance. This might have an impact on some Reactome services and we apologize for any inconvenience.

Platelet homeostasis

Stable Identifier
R-HSA-418346
Type
Pathway
Species
Homo sapiens
Compartment
Locations in the PathwayBrowser
Summation

Under normal conditions the vascular endothelium supports vasodilation, inhibits platelet adhesion and activation, suppresses coagulation, enhances fibrin cleavage and is anti-inflammatory in character. Under acute vascular trauma, vasoconstrictor mechanisms predominate and the endothelium becomes prothrombotic, procoagulatory and proinflammatory in nature. This is achieved by a reduction of endothelial dilating agents: adenosine, NO and prostacyclin; and by the direct action of ADP, serotonin and thromboxane on vascular smooth muscle cells to elicit their contraction (Becker et al. 2000). Cyclooxygenase-2 (COX-2) and endothelial nitric oxide synthase (eNOS) are primarily expressed in endothelial cells. Both are important regulators of vascular function. Under normal conditions, laminar flow induces vascular endothelial COX-2 expression and synthesis of Prostacyclin (PGI2) which in turn stimulates endothelial Nitric Oxide Synthase (eNOS) activity. PGI2 and NO both oppose platelet activation and aggregation, as does the CD39 ecto-ADPase, which decreases platelet activation and recruitment by metabolizing platelet-released ADP.

Literature References
Participants
Participant Of
hasEvent
Orthologous Events