[The vascular endothelium--a multifunctional organ].

Area of Science:

• Vascular biology
• Endothelial cell function
• Hemostasis and thrombosis

Context:

• The endothelium, a single layer of cells lining blood vessels, is increasingly recognized for its multifaceted roles beyond barrier function.
• Perturbations in endothelial cell function are implicated in numerous pathological conditions.
• Understanding endothelial cell behavior is critical for comprehending vascular health and disease.

Purpose:

• To summarize the diverse functions of the vascular endothelium.
• To highlight the transition of endothelial cells from an antithrombogenic to a thrombogenic state.
• To underscore the endothelium's involvement in inflammation and angiogenesis.

Summary:

• The vascular endothelium regulates hemostasis, thrombosis, vasomotor tone, inflammation, and angiogenesis.
• Quiescent endothelium is antithrombogenic, but perturbed endothelial cells become thrombogenic.
• Endothelial cells produce vasodilators (e.g., endothelial-derived relaxing factor, prostacyclin) and vasoconstrictors (e.g., endothelins).
• Leukocyte adhesion molecules and HLA antigens on endothelial surfaces mediate inflammatory interactions.
• Endothelial dysfunction is central to diseases like atherosclerosis, preeclampsia, hemolytic uremic syndrome, and vasculitis.

Impact:

• Provides a comprehensive overview of endothelial cell functions in health and disease.
• Emphasizes the critical role of the endothelium in inflammatory processes and vascular pathologies.
• Highlights the endothelium's significance in the pathogenesis of major cardiovascular and systemic diseases.