Glicentin (By similarity) belongs to Glucagon. Glicentin (By similarity) is expressed in Glucagon is secreted in the A cells of the islets of Langerhans. GLP-1, GLP-2, oxyntomodulin and glicentin are secreted from enteroendocrine cells throughout the gastrointestinal tract. GLP-1 and GLP-2 are also secreted in selected neurons in the brain. Glicentin is a 69-amino-acid peptide containing glucagon and oxyntomodulin sequences in the molecule. Glicentin is a major form of gut glucagon-like immunoreactants (Gut GLIs). In mammalian small intestine, proglucagon is processed into glicentin, oxyntomodulin, and glucagon -like peptide 1(GLP-1) and glucagon -like peptide 2 (GLP-2). GLP-1(7–37) and GLP-1(7–36)amide have been isolated from the intestine and pancreas. It has been known that the GLP-1 sequence is well conserved between species in all mammals studied. Using synthetic peptides, several investigators have demonstrated that in contrast to GLP-1 (1–37), truncated GLP-1(7–36)amide and GLP-1(7–37) have several physiological effects.