Colokinetic effect of an insulin-like peptide 5-related agonist of the RXFP4 receptor

Abstract

Background: Insulin-like peptide 5 (INSL5) is a hormone stored in colonic enteroendocrine cells that also contain the unrelated hormones, GLP-1 and PYY. It acts at the relaxin family peptide 4, RXFP4, receptor. RXFP4 is expressed by enteric neurons in the colon, and it has been speculated that INSL5, through its action on enteric neurons, might be involved in the control of colonic contractions. Similar to insulin and relaxin, INSL5 consists of A and B peptide chains linked by three disulfide bonds, two between the chains and one intrinsic to the A chain. Because of its complex structure, it is difficult to synthesize and to prepare peptide analogues to investigate its roles. We have recentl..