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

The beta-1 and beta-3 adrenergic receptors are distinct G protein-coupled receptors (GPCRs) that mediate the effects of the sympathetic nervous system through the Gs-adenylyl cyclase-cAMP pathway. The beta-1 adrenergic receptor (ADRB1) is primarily located in the heart, where its activation by norepinephrine increases heart rate and contractility; consequently, beta-1 antagonists are widely used to treat hypertension, arrhythmias, and heart failure (UniProt P08588; PubChem CID 4171). The beta-3 adrenergic receptor (ADRB3) is predominantly expressed in adipose tissue and the urinary bladder, playing key roles in lipolysis, thermogenesis, and detrusor muscle relaxation (UniProt P13945). Agonists of the beta-3 receptor, such as mirabegron, are clinically utilized for the management of overactive bladder by improving storage capacity without affecting voiding pressure (FDA Label for Myrbetriq). Because these two receptors have different tissue distributions and physiological effects, they are typically targeted separately in clinical practice, though some drugs may exhibit cross-reactivity depending on their selectivity profiles.

Other names

Beta-1 adrenoceptorBeta-3 adrenoceptorADRB1ADRB3B1ARB3AR

Beta-1 adrenergic receptor antagonists inhibit sympathetic stimulation of the heart to lower heart rate and blood pressure, while beta-3 adrenergic receptor agonists stimulate the detrusor muscle to relax, increasing bladder capacity.