Endothelin receptor ET_A polyclonal antibody

Endothelins are vasoactive peptides that exist in three forms (ET-1, ET-2, and ET-3), and function in the maintenance of vascular tone via two identified seven transmembrane-spanning domain-containing G protein-coupled receptors (GPCR), endothelin A (ETA) and endothelin B (ETB). The human ETA receptor is primarily expressed in vascular smooth muscle cells, including those of the heart (also in myocytes), lung, and brain, and its stimulation generally results in vasoconstriction. Activation of ETA receptors can be stimulated by binding of ET-1 and ET-2, but not ET-3. triggering the release of vasorelaxive factors such as nitric oxide (NO) and prostanoids from endothelial cells. Human ETB receptors are primarily expressed in endothelial cells lining the vessel walls of the lungs, heart, and brain, and in contrast to ETA receptors, stimulation generally results in transient vasodilation. Activation of ETB receptors can be stimulated by binding of all three endothelins, triggering the release of vasorelaxive factors such as nitric oxide (NO) and prostanoids from endothelial cells. Both ETA and ETB receptors signal primarily via coupling to Gq/11 alpha subunits, although Gi/o and Gs coupling are also established mechanisms of endothelin signaling, resulting in stimulation of phospholipases C, A2, and D.