Beta-1 and Beta-2 adrenergic receptor (β1-AR and β2-AR)

Beta-1 and Beta-2 adrenergic receptors are members of the G protein-coupled receptor (GPCR) superfamily, comprised of seven transmembrane domains, and are key mediators of the physiological effects of catecholamines such as epinephrine and norepinephrine. Beta-1 adrenergic receptors (β1-AR, ADRB1) are primarily found in cardiac tissue, where they regulate heart rate and contractility, as well as in the kidney (renin release). Beta-2 adrenergic receptors (β2-AR, ADRB2) are predominantly expressed in smooth muscle tissues (such as bronchioles and vasculature) and mediate bronchodilation, vasodilation, and metabolic effects like glycogenolysis and lipolysis. Both receptor subtypes are key drug targets in the treatment of cardiovascular and respiratory diseases, with distinct and overlapping clinical roles depending on tissue distribution and drug selectivity[1][2][3][4][5][7]. They are structurally similar, each interacting with heterotrimeric Gs proteins to initiate intracellular signaling cascades and increase cAMP. Numerous drugs target these receptors as agonists or antagonists for the treatment of conditions such as heart failure, hypertension, arrhythmias, asthma, and COPD. If structured information is needed for each subtype separately, entries can be divided as "Beta-1 adrenergic receptor" and "Beta-2 adrenergic receptor."

Other names

Beta-adrenergic receptor subtype 1Beta-adrenergic receptor subtype 2β1-adrenoceptorβ2-adrenoceptorADRB1ADRB2beta-adrenergic receptorbeta-adrenoceptor

Antagonists (blockers): competitively inhibit catecholamine binding, reducing heart rate, contractility (β1), and bronchospasm (β2)[4]. Agonists: activate Gs protein-coupled signaling, increase cAMP, enhance cardiac contractility (β1), and cause bronchodilation (β2)[1][2][4].