Alpha-2B adrenergic receptor (ADRA2B) (ADRA2B)

The Alpha-2B adrenergic receptor (ADRA2B) is a G protein-coupled receptor (GPCR) that belongs to the adrenergic receptor family and is primarily associated with the Gi/o signaling pathway [1, 4]. It plays a critical role in the regulation of the sympathetic nervous system by mediating the inhibitory effects of catecholamines like norepinephrine and epinephrine [3, 4]. Unlike the alpha-2A subtype, which is widely distributed in the central nervous system and mediates sedation and hypotension, the alpha-2B subtype is prominently expressed in vascular smooth muscle, where it mediates peripheral vasoconstriction and the initial hypertensive response to alpha-2 agonists [2, 12]. Beyond cardiovascular regulation, ADRA2B is involved in metabolic processes such as the inhibition of insulin secretion and lipolysis, and it has been linked to the modulation of emotional memory and pain perception [1, 9]. Drugs targeting this receptor, such as clonidine and dexmedetomidine, are used clinically for their sedative, analgesic, and antihypertensive properties, although their lack of subtype selectivity often leads to side effects like bradycardia and dry mouth [2, 5, 10]. Genetic variations in the ADRA2B gene, particularly a common deletion polymorphism, have been associated with altered receptor desensitization and increased risk for cardiovascular and metabolic disorders [1, 9].

Other names

Alpha-2B adrenoceptorAlpha-2B adrenoreceptorADRA2L1ADRA2RL1ADRARL1ALPHA2BARalpha-2BARFAME2

Agonism of the Gi/o protein-coupled pathway, leading to the inhibition of adenylate cyclase, reduction of intracellular cAMP levels, suppression of voltage-gated calcium channels, and activation of G protein-coupled inwardly rectifying potassium (GIRK) channels [2, 4, 10].