Beta-adrenergic receptor (ADRB) (ADRB)

Beta-adrenergic receptors (ADRBs) are a class of G protein-coupled receptors (GPCRs) that mediate the physiological responses to the endogenous catecholamines epinephrine and norepinephrine (StatPearls, NBK534230). They are categorized into three main subtypes—$eta_1$, $eta_2$, and $eta_3$—each with distinct tissue distributions and physiological roles (UniProt, P08588, P07550). $eta_1$ receptors are primarily located in the heart and kidneys, where they regulate heart rate, contractility, and renin release. $eta_2$ receptors are found in the smooth muscle of the airways and blood vessels, facilitating bronchodilation and vasodilation, while $eta_3$ receptors are involved in lipolysis and thermogenesis in adipose tissue (PubMed, PMID: 29061472). These receptors are critical therapeutic targets; $eta$-blockers are widely used to manage cardiovascular conditions like hypertension, heart failure, and arrhythmias by reducing cardiac workload (NIH, MedlinePlus). Conversely, $eta_2$-agonists are essential in treating respiratory diseases such as asthma and COPD by promoting airway relaxation (StatPearls, NBK526042).

Other names

Beta-adrenoceptorAdrenoceptor beta$eta$-adrenergic receptorADRB1ADRB2ADRB3

Agonists bind to the receptor to activate Gs proteins, stimulating adenylyl cyclase and increasing intracellular cAMP levels (StatPearls, NBK534230). Antagonists (beta-blockers) competitively inhibit the binding of endogenous catecholamines to prevent sympathetic overstimulation (PubMed, PMID: 10403502).