Relamorelin (RM-131) TFA, a pentapeptide ghrelin analog, is a selective ghrelin/growth hormone secretagogue receptor (GHSR) agonist with a Ki of 0.42 nM for GHS-1a receptor. Relamorelin TFA is centrally penetrant. Relamorelin TFA increases growth hormone levels and accelerates gastric emptying. Relamorelin TFA has the potential for cachexia, gastroparesis, and gastric/intestinal dysmobility disorders research[1][2][3][4][5].
Relamorelin (RM-131) TFA shows ∼3 times greater affinity for GHS-1a (Ki=0.42 nM) than native ghrelin (Ki=1.12 nM). Relamorelin TFA 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].
Relamorelin (RM-131; 50-500 nmol/kg/day; s.c.; continuous infusion for 5 days) TFA decreases the loss of body mass and fat mass. Relamorelin (500 nmol/kg/day; continuous infusion for 5 days) TFA increases the food intake and weight gain in rats[1].RM-131 (250-500 nmol/kg; a single s.c.) TFA stimulates acute food intake in wt but not growth hormone secretagogue receptor (GHR) ko mice[2].
[1]. DeBoer MD, et, al. Ghrelin treatment causes increased food intake and retention of lean body mass in a rat model of cancer cachexia. Endocrinology. 2007 Jun;148(6):3004-12.
[2]. Fischer K, et, al. The Pentapeptide RM-131 Promotes Food Intake and Adiposity in Wildtype Mice but Not in Mice Lacking the Ghrelin Receptor. Front Nutr. 2015 Jan 12;1:31.
[3]. Zatorski H, et, al. Relamorelin and other ghrelin receptor agonists - future options for gastroparesis, functional dyspepsia and proton pump inhibitors-resistant non-erosive reflux disease. J Physiol Pharmacol. 2017 Dec;68(6):797-805.
[4]. Matthew Heckroth, et al. Nausea and Vomiting in 2021: A Comprehensive Update. J Clin Gastroenterol. 2021 Apr 1;55(4):279-299.
[5]. Victor Chedid, et al. Relamorelin for the treatment of gastrointestinal motility disorders. Expert Opin Investig Drugs. 2017 Oct;26(10):1189-1197.