Beta-3 adrenergic receptor (β3-AR (also commonly ADRB3))

Beta-3 adrenergic receptor Overview

The beta-3 adrenergic receptor (β3-AR), encoded by the ADRB3 gene, is a G protein-coupled receptor primarily expressed in adipose tissue, where it mediates catecholamine-induced lipolysis and thermogenesis via activation of adenylate cyclase and increased cAMP[1][5][7][8]. It also plays important roles in relaxation of bladder smooth muscle, regulation of cardiac function, and possibly central nervous system processes. The receptor is a therapeutic target for conditions including overactive bladder, metabolic syndrome (obesity and diabetes), and is being explored for other indications such as heart failure and depression[1][2][4]. Agonists such as mirabegron and vibegron are already approved for overactive bladder, while other compounds are under investigation or used for research. Polymorphisms in ADRB3 have been linked to obesity and metabolic risk[5][7], and there are ongoing studies into its potential role in cardiovascular and neoplastic diseases. Like other adrenergic receptors, inappropriate activation/inhibition may involve cardiovascular risks or impact CNS function.

Mechanism of Action

Agonism: Activation promotes relaxation of smooth muscle (notably bladder), enhances lipolysis in adipose tissue, induces thermogenesis, and modulates cardiac response (generally via Gs protein/adenylate cyclase/cAMP pathway)[1][2][3][4][8]. Antagonism: Inhibition can block receptor-mediated effects, though clinical use is limited[1].

Biological Functions

Safety Considerations

Interacting Drugs

Associated Biomarkers