Glucagon-like peptides GLP-1 and GLP-2, predicted products of the glucagon gene, are secreted separately from pig small intestine but not pancreas.
We developed specific antibodies and RIAs for glucagon-like peptides 1 and 2 (GLP-1 and GLP-2), two predicted products of the glucagon gene, and studied the occurrence, nature, and secretion of immunoreactive GLP-1 and GLP-2 in pig pancreas and small intestine. Immunoreactive GLP-1 and GLP-2 were identified in glucagon-producing cells of the pancreatic islets, and in glicentin-producing cells of the small intestine. Immunoreactive GLP-1 and 2 in intestinal extracts corresponded in molecular size to peptides synthesized according to the predicted structure. By reverse phase HPLC, intestinal and synthetic GLP-1 behaved similarly, whereas synthetic and intestinal GLP-2 differed. Pancreatic extracts contained a large peptide with both GLP-1 and GLP-2 immunoreactivity. Secretion was studied using isolated perfused pig pancreas during arginine stimulation, and isolated perfused pig ileum during either luminal glucose stimulation or vascular administration of the neuropeptide, gastrin-releasing peptide (GRP). Immunoreactive GLP-1 and GLP-2 were secreted in parallel with pancreatic glucagon and intestinal glicentin. The molecular forms of secreted immunoreactive GLP-1 and 2 corresponded to those identified in the tissue extracts.
D000818:Animals; D001120:Arginine / Q000494:pharmacology; D019886:Gastrin-Releasing Peptide; D005934:Glucagon / Q000378:metabolism; D052216:Glucagon-Like Peptide 1; D053767:Glucagon-Like Peptide 2; D005947:Glucose / Q000494:pharmacology; D006651:Histocytochemistry; D007124:Immunoenzyme Techniques; D007421:Intestine, Small / Q000032:analysis / Q000187:drug effects / Q000378:metabolism*; D010179:Pancreas / Q000032:analysis / Q000187:drug effects / Q000378:metabolism*; D010455:Peptides / Q000032:analysis / Q000378:metabolism* / Q000494:pharmacology; D052336:Proglucagon; D011498:Protein Precursors / Q000378:metabolism; D013552:Swine
D053767:Glucagon-Like Peptide 2; D010455:Peptides; D011498:Protein Precursors; D052336:Proglucagon; D019886:Gastrin-Releasing Peptide; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D001120:Arginine; D005947:Glucose