GLP Receptor

The GLP receptors contain two family members, GLP-1 receptor (GLP1R, or GLP-1R) and GLP-2 receptor (GLP2R or GLP-1R), activated by the glucagon-like peptides (GLPs). GLPs are s secreted by intestinal cells; causes insulin release; inhibits glucagon secretion, appetite, and energy intake; and delays gastric emptying because GLP receptors are located on the gut, pancreas, brainstem, hypothalamus, and vagal-afferent nerves. GLP-1 has only one known receptor, GLP1R, and regulates gut motility, appetite, islet function, and glucose homeostasis, whereas GLP-2, the agonist of GLP2R, enhances intestinal nutrient absorption. GLP-1R agonists are used to treat diabetes and obesity, and a GLP-2R agonist is approved to treat short bowel syndrome. An investigation of the actions of GLP receptor activation on gallbladder motility has demonstrated that GLP-2 receptor activation increases gallbladder volume in vivo and decreases spontaneous activity in GBSM bundles ex vivo. Like the inhibitory transmitters, which elicit their actions via an adenylate cyclase-protein kinase A-KATP channel pathway, the GLP-2 receptor signals through this same pathway.