Adrenergic Receptor

Adrenergic receptors (adrenoceptors) are a class of G protein-coupled receptors that mediate the physiological effects of catecholamines such as norepinephrine (noradrenaline) and epinephrine (adrenaline). They play a central role in the sympathetic nervous system's "fight-or-flight" response, influencing cardiovascular function, metabolism, and smooth muscle tone. The receptors are divided into alpha (α) and beta (β) classes, each with further subtypes (α1A, α1B, α1D; α2A, α2B, α2C; β1, β2, β3). Each subtype exhibits distinct tissue distribution and functional roles. Activation or blockade of adrenergic receptor subtypes produces diverse effects and are widely used therapeutically.

Other names

AdrenoceptorAdrenergic Receptor Family

Agonists bind to the receptor, activating associated G proteins by exchanging GDP for GTP on the alpha subunit. This leads to downstream signaling events such as activation or inhibition of adenylyl cyclase or phospholipase C depending on receptor subtype. Antagonists block the receptor, preventing agonist binding and subsequent activation of downstream signaling pathways.