Beta-3 adrenergic receptor (ADRB3) (ADRB3)

The Beta-3 adrenergic receptor (ADRB3) is a G protein-coupled receptor primarily expressed in adipose tissue and the urinary bladder (UniProt: P13945). Its activation triggers the Gs-adenylyl cyclase-cAMP signaling pathway, which mediates several physiological responses including lipolysis and thermogenesis (NCBI Gene: 155). In the urinary system, ADRB3 activation leads to the relaxation of the detrusor smooth muscle, thereby increasing bladder capacity and facilitating urine storage (PubMed: 24184877). This mechanism makes the receptor a primary therapeutic target for overactive bladder (OAB), providing a distinct alternative to traditional antimuscarinic agents (StatPearls: NBK493161). Clinically approved drugs such as mirabegron and vibegron act as selective agonists to alleviate symptoms of urgency and frequency (FDA: Mirabegron Label). Beyond urology, ADRB3 is investigated for its potential role in treating metabolic disorders like obesity and type 2 diabetes due to its influence on energy expenditure (PubMed: 30103319). It also plays a role in the cardiovascular system, where it may exert a negative inotropic effect in the heart, contrasting with the stimulatory effects of beta-1 and beta-2 receptors (PubMed: 12855480). Therapeutic development continues to focus on improving selectivity to minimize off-target cardiovascular effects such as hypertension.

Other names

ADRB3Beta-3 adrenoceptorBeta-3 adrenoreceptorB3ARBeta-3 adrenergic receptor

Agonism of the beta-3 adrenergic receptor activates the Gs protein-adenylyl cyclase-cAMP pathway, leading to the relaxation of smooth muscle (particularly the detrusor muscle in the bladder) and the stimulation of lipolysis in adipose tissue (PubMed: 24184877).