註釋 G protein-coupled receptors (GPCRs) are a diverse super family of seven transmembrane spanning proteins whose primary function is to initiate the activation of intracellular signalling pathways following stimulation by extracellular stimuli, which include photons, amines, lipids, ions, peptides and proteins. Due to the ubiquitous expression of GPCRs throughout various tissues, they are implicated in the regulation of a variety of diverse physiological processes, such as secretion of the blood glucose controlling hormones insulin, glucagon and somatostatin from islets. As a result, GPCRs are being identified as therapeutic targets for the treatment of type-2 diabetes. Despite the large array of potential GPCR targets available, only a handful of GPCRs have proven to be successful clinical targets, which may partially be due to the lack of availability of suitable translational models that reflect the human GPCR landscape. The aim of the experiments described in this thesis was to compare the mRNA expression profiles of all GPCRs (the GPCRome) and all GPCR peptide ligands (the Secretome) in human and mouse islets in order to determine the suitability of using mouse islets as a translational model for predicting the role of islet GPCRs and GPCR peptide ligands in human islet function. In addition, some experiments demonstrate how the GPCRome and Secretome data were used to assess the role of CXCL14 in islet function. 