Ulimorelin
Ulimorelin
Chemical compound
Ulimorelin (INN, USAN) (developmental code name TZP-101) is a drug with a modified cyclic peptide structure which acts as a selective agonist of the ghrelin/growth hormone secretagogue receptor (GHSR-1a).[1] Unlike many related drugs, ulimorelin has little or no effect on growth hormone (GH) release in rats.[2] However, like ghrelin and other ghrelin agonists, ulimorelin does stimulate GH release with concomitant increases in insulin-like growth factor 1 (IGF-1) in humans.[3] It has been researched for enhancing gastrointestinal motility, especially in gastroparesis[4] and in aiding recovery of bowel function following gastrointestinal surgery, where opioid analgesic drugs used for post-operative pain relief may worsen existing constipation.[5][6][7][8] While ulimorelin has been shown to increase both upper and lower gastrointestinal motility in rats,[8] and showed promising results initially in humans,[4][6] it failed in pivotal clinical trials in post operative ileus.[7]
A common side effect of ghrelin is reduced blood pressure. Ulimorelin has been shown to inhibit vasoconstriction of rat arteries in vitro elicited by the α1-adrenoceptors agonists phenylephrine and methoxamine, and to increase artery tension at high concentrations.[9] Effects on blood pressure, however, were not observed in human clinical trials.[4][7]