Amibegron hydrochloride, a selective β3-adrenoceptor agonist (EC50: 3.5 nM for β-adrenoceptor in rat colon), exhibits anxiolytic and antidepressant activity.

β-adrenoceptor: 499 nM , β-adrenoceptor:（EC50）3.5 nM

Amibegron hydrochloride (SR 58611A) is a selective β-adrenoceptor agonist (EC50: 499 nM in rat uterus) [1]. It has minimal effect on β1- and β2-adrenoceptors and on the uptake of 5-HT, noradrenaline (NA), and dopamine (DA) from rat brain tissue (IC50s: 4.6 and 1.2, 0.58, 2.5, and 3.2 μM). It exhibits no effect on 5-HT1A, 5-HT2, MAO-A, and MAO-B (IC50 > 10 μM) [2].

Amibegron hydrochloride (0.1 to 0.3 mg/kg, i.p.) potentiates the toxicity produced by yohimbine in mice. Amibegron hydrochloride (0.6 and 2 mg/kg, i.p.) is also active in the learned helplessness model of antidepressant-like activity in rats [2]. Amibegron hydrochloride (3 and 10 mg/kg, p.o.) increases the synthesis of 5-HT and tryptophan (Trp) levels in several rodent brain areas such as cortex, hippocampus, hypothalamus. In addition, Amibegron hydrochloride (10 mg/kg, p.o.) promotes the release of 5-HT in the rat prefrontal cortex. Systemic (3 mg/kg, i.v.) or chronic administration of SR58611A (10 mg/kg, p.o.) does not affect the activity of serotonergic neurons in the rat dorsal raphe nucleus [3].