YM348

YM348 is a potent and orally active 5-HT_2C receptor agonist, which shows a high affinity for cloned human 5-HT_2C receptor (K_i: 0.89 nM). IC50 & Target: Ki: 0.89±0.05 nM (5-HT_2C receptor), 2.5±0.5 nM (5-HT_2B receptor), 13±2 nM (5-HT_2A receptor)^[1]
EC50: 1.0±0.2 nM (5-HT_2C receptor), 3.2±3 (5-HT_2B receptor) , 93±10 nM (5-HT_2A receptor)^[1] In Vitro: YM348 has high affinity for cloned human 5-HT_2C receptors with a K_i value of 0.89 nM and lower affinities for human-cloned 5-HT_2B (K_i: 2.5 nM) and 5-HT_2A receptors (K_i: 13 nM). To assess the binding specificity of YM348, a broad evaluation of an additional 46 binding sites including several other 5-HT receptor subtypes (1A, 1B, 1D, 3, 4, 5A, 6, 7) is performed. IC₅₀ values of YM348 are found to be >1 μM for all of the binding sites except for the human 5-HT_1A receptors (K_i: 130 nM), bovine 5-HT_1D receptors (K_i: 481 nM), human 5-HT₇ receptors (K_i: 177 nM), and human α_2A receptors (K_i: 126 nM).YM348 exhibits a full-agonistic activity on human 5-HT_2A and 5-HT_2B receptors. The EC₅₀ values of YM348 for 5-HT_2C, 5-HT_2A, and 5-HT_2B receptors are 1.0, 93 and 3.2 nM, respectively^[1]. In Vivo: Oral administration of YM348 induces penile erections and hypolocomotion in rats, being completely inhibited by a selective 5-HT_2C receptor antagonist, SB242084. YM348 inhibits spontaneous activity in a dose-dependent manner with a minimum effective dose of 0.203 mg/kg^[1].