Relenopride (hydrochloride)

Relenopride (YKP10811) hydrochloride is a specific and selective 5-HT₄ receptor agonist (K_i=4.96 nM). Relenopride hydrochloride has 120-fold and 6-fold lower affinity, respectively, for 5-HT_2A (K_i=600 nM) and 5-HT_2B receptors (K_i=31 nM) than for 5-HT₄. Relenopride hydrochloride increases gastrointestinal (GI) motility^[1][2]. In Vitro: Relenopride hydrochloride do not show any significant off-target binding to any other receptors, enzymes, orserotonin-receptor subtypes at 1 μM, except for binding to the 5-HT_2A receptor and the 5-HT_2B receptor. Relenopride hydrochloride shows antagonist activity at the 5-HT_2B receptor with an IC₅₀ of 2.1 μM and no significant activity at the 5-HT_2A receptor up to 10 μM. Relenopride hydrochloride shows no activity against serotonin-receptor subtypes 5-HT_1B, 5-HT_1D, or 5-HT_2A at 1 nM to 10 μM, or for serotonin-receptor subtype 5-HT₇ at 10 nM to 30 μM^[1].