The function of ADRA2B (adrenoceptor alpha 2B, ENSG00000274286) is as follows. Alpha-2 adrenergic receptors are G protein-coupled receptors for catecholamines that activate G(i/o) protein pathway, thereby promoting adenylyl cyclase inhibition, ERK1/2 stimulation, and voltage- gated calcium channels suppression (PubMed:11056163, PubMed:2164221, PubMed:2172775, PubMed:23105096, PubMed:26811329). Control a variety of physiological processes, such as regulation of blood pressure, lipolysis and insulin release (PubMed:2164221). The rank order of potency for agonists of ADRA2B is clonidine > norepinephrine > epinephrine = oxymetazoline > dopamine > p-tyramine = phenylephrine > serotonin > p-synephrine / p-octopamine. For antagonists, the rank order is yohimbine > chlorpromazine > phentolamine > mianserine > spiperone > prazosin > alprenolol > propanolol > pindolol (PubMed:2164221, PubMed:2172775). {ECO:0000269|PubMed:11056163, ECO:0000269|PubMed:2164221, ECO:0000269|PubMed:2172775, ECO:0000269|PubMed:23105096, ECO:0000269|PubMed:26811329}.