Capillary endothelial cell

Capillary endothelial cells are specialized epithelial-like cells that form the innermost lining (endothelium) of the smallest blood vessels—capillaries—throughout the body. They create a selective barrier between circulating blood and surrounding tissues, regulating the exchange of gases (oxygen/carbon dioxide), nutrients, water, lipids, metabolic waste products like urea, and immune cell trafficking. These cells play essential roles in maintaining tissue homeostasis through control over vascular permeability; they also participate actively in processes such as angiogenesis (new vessel formation), regulation of vascular tone via mediators like nitric oxide for vasodilation/constriction,[1] hemostasis/thrombosis prevention,[8] inflammation signaling,[8] and tissue repair. Capillary endothelial dysfunction is implicated in numerous diseases including cardiovascular disorders,[1] cancer progression/metastasis through abnormal angiogenesis,[9] chronic inflammation with increased permeability leading to edema,[8] diabetic microvascular complications affecting organs like retina/kidney,[2] among others. While many therapeutics act upon molecular targets present on capillary endothelium—such as VEGF receptors for antiangiogenic therapy—the term "capillary endothelial cell" itself does **not** refer to a specific druggable protein/receptor/enzyme/transporter but rather an entire class/type of somatic cell. Therefore it is **not considered** a canonical therapeutic target molecule but rather an important cellular compartment involved in health and disease biology.[5] If you require information about specific molecular targets *expressed* by capillary endothelium—such as "Vascular Endothelial Growth Factor Receptor 2" or "Integrin αvβ3"—please specify those molecules individually.

Other names

Capillary endotheliumMicrovascular endothelial cellBlood capillary endothelial cell

Drugs may indirectly affect capillary endothelial cells via inhibition or activation of pathways like VEGF signaling for antiangiogenic therapy in cancer or eye disease; e.g., anti–VEGF antibodies inhibit angiogenesis by blocking VEGF action on these cells.[9]