Relamorelin

Relamorelin (RM-131), a pentapeptide ghrelin analog, is a selective ghrelin/growth hormone secretagogue receptor (GHSR) agonist with a K_i of 0.42 nM for GHS-1a receptor. Relamorelin is centrally penetrant. Relamorelin increases growth hormone levels and accelerates gastric emptying. Relamorelin has the potential for cachexia, gastroparesis, and gastric/intestinal dysmobility disorders research^[1][2][3][4]. IC50 & Target: Ki: 0.42 nM (GHS-1a)^[1] In Vitro: Relamorelin (RM-131) shows ～3 times greater affinity for GHS-1a (K_i=0.42 nM) than native ghrelin (K_i=1.12 nM). Relamorelin is 6 times more potent (EC₅₀=0.71 nM) in activating the GHS-1a receptor than native ghrelin (EC₅₀=4.2 nM) as assessed in vitro by calcium mobilization^[1].
In Vivo: Relamorelin (RM-131; 50-500 nmol/kg/day; s.c.; continuous infusion for 5 days) decreases the loss of body mass and fat mass. Relamorelin (500 nmol/kg/day; continuous infusion for 5 days) increases the food intake and weight gain in rats^[1].
RM-131 (250-500?nmol/kg; a single s.c.) stimulates acute food intake in wt but not growth hormone secretagogue receptor (GHR) ko mice^[2].