Beta-adrenoceptor (ADRB) (ADRB)

Beta-adrenoceptors (also known as beta-adrenergic receptors) are a class of G protein-coupled receptors (GPCRs) that mediate the physiological effects of the sympathetic nervous system in response to catecholamines like epinephrine and norepinephrine [4, 9]. This receptor family consists of three primary subtypes: beta-1 (ADRB1), beta-2 (ADRB2), and beta-3 (ADRB3), each with distinct tissue distributions and physiological roles [1, 12]. Beta-1 receptors are predominantly found in the heart and kidneys, where they regulate heart rate, contractility, and renin release [9]. Beta-2 receptors are widely expressed in smooth muscle, particularly in the airways and blood vessels, mediating bronchodilation and vasodilation [7, 13]. Beta-3 receptors are primarily located in adipose tissue and the bladder, playing roles in lipolysis, thermogenesis, and detrusor muscle relaxation [5, 15]. These receptors are critical therapeutic targets; beta-blockers are used to manage cardiovascular conditions such as hypertension and heart failure, while beta-agonists are essential for treating respiratory diseases like asthma and COPD [2, 11, 14].

Other names

Beta-adrenergic receptorBeta-adrenoceptorADRBB-ARBeta-adrenoreceptor

Drugs targeting beta-adrenoceptors function as either agonists or antagonists. Agonists bind to the receptor and stabilize an active conformation that couples to Gs proteins, stimulating adenylyl cyclase to increase intracellular cAMP levels, which activates protein kinase A (PKA) to mediate effects such as bronchodilation or increased cardiac contractility [4, 9, 13]. Antagonists, commonly known as beta-blockers, competitively inhibit the binding of endogenous catecholamines (epinephrine and norepinephrine), thereby reducing sympathetic activity in the heart and other tissues to treat conditions like hypertension and heart failure [3, 14].