Alpha-1 Adrenergic Receptor

Alpha-1 adrenergic receptors are G protein-coupled receptors located primarily on the smooth muscle cells of blood vessels, but also in other tissues like the heart and liver. Upon activation by endogenous catecholamines such as norepinephrine, these receptors couple to Gq proteins, leading to the activation of phospholipase C and subsequent increases in intracellular calcium. This signaling cascade primarily mediates vasoconstriction, playing a crucial role in regulating systemic blood pressure and local blood flow.