Beta-1 adrenergic receptor and beta-3 adrenergic receptor (ADRB1/ADRB3)

The Beta-1 and Beta-3 adrenergic receptors are members of the G protein-coupled receptor (GPCR) superfamily that mediate the physiological responses to the catecholamines norepinephrine and epinephrine (UniProt P08588, P13945). Beta-1 receptors are primarily expressed in the heart and kidneys, where they play a central role in increasing heart rate, cardiac contractility, and the secretion of renin (StatPearls, "Physiology, Adrenergic Receptors"). Beta-3 receptors are found predominantly in brown and white adipose tissue and the detrusor muscle of the bladder, where they regulate lipolysis, thermogenesis, and bladder capacity (PubMed PMID: 30130453). Therapeutically, Beta-1 receptors are targeted by antagonists (beta-blockers) to manage cardiovascular conditions like hypertension and chronic heart failure by reducing sympathetic overstimulation (NCBI, "Beta Blockers"). Beta-3 receptors are targeted by selective agonists, such as mirabegron, to treat overactive bladder by promoting muscle relaxation during the storage phase (PubChem CID 11345969). Because these receptors are involved in critical autonomic and metabolic functions, pharmacological interventions must maintain high selectivity to minimize adverse effects like unintended cardiac stress or metabolic dysregulation.

Other names

Beta-1 adrenoceptorBeta-3 adrenoceptorADRB1ADRB3B1ARB3ARBeta-1 adrenoreceptorBeta-3 adrenoreceptor

Drugs targeting these receptors act as either agonists or antagonists to modulate intracellular cyclic AMP (cAMP) levels via Gs protein coupling. Beta-1 antagonists (beta-blockers) reduce heart rate and blood pressure by blocking catecholamine binding in cardiac tissue, while Beta-3 agonists promote smooth muscle relaxation in the bladder and stimulate metabolic processes in adipose tissue (StatPearls, "Physiology, Adrenergic Receptors"; PubMed PMID: 29033142).