title: Synthetic analogs of cholecystokinin terminal tetrapeptide that stimulate insulin but not glucagon release from pancreatic islets.
abstract: Two synthetic analogs of CCK-4, Glp-Met-Asp-Phe-NH2 (I) and Pro-Met-Asp-Phe-NH2 (II) reported earlier to stimulate insulin release from the isolated rat pancreatic islets in vitro at concentrations as low as 10(-10) M, have now been found to be totally ineffective as glucagon releasers at concentrations as high as 10(-6) M or higher. It is evident that the replacement of Trp in CCK-4 by Glp and Pro residues leads to peptides which exhibit insulin releasing activity without stimulating the release of glucagon.
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D005755:Gastrins / Q000494:pharmacology*; D005934:Glucagon / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism*; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D013758:Tetragastrin / Q000138:chemical synthesis / Q000494:pharmacology*
chemical_list: D005755:Gastrins; D007328:Insulin; D010446:Peptide Fragments; D013758:Tetragastrin; D005934:Glucagon