title: Binding sites for peptide-histidine-isoleucine (PHI) on rat insulinoma-derived RINm5F cells.
abstract: Specific binding sites for 125I-labelled rat peptide-histidine-isoleucine (PHI) were identified on rat insulinoma-derived RINm5F cells. The concentrations of peptides producing half-maximal displacement of label were rat PHI, 0.36 +/- 0.14 nM, vasoactive intestinal polypeptide (VIP), 0.38 +/- 0.13 nM and secretin, approximately 0.2 microM. Glucagon and glucagon-like peptide-1(7-36)amide were without effect on binding. PHI and VIP produced dose-dependent increases in cAMP production in the cells that were significantly (P less than 0.05) above unstimulated rates for ligand concentrations between 10(-8) and 10(-6) M. Both PHI and VIP produced a small but significant (P less than 0.05) enhancement in the rate of release of immunoreactive insulin from the cells but the effect was not dose dependent.
authors.affiliation: Clinical Research Group for Gastrointestinal Endocrinology, Max-Planck-Gesellschaft, University of Göttingen, F.R.G.
authors.forename: R
authors.initials: R
authors.lastname: Göke
authors.forename: J M
authors.initials: JM
authors.lastname: Conlon
mesh_terms: D007516:Adenoma, Islet Cell / Q000378:metabolism*; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D000242:Cyclic AMP / Q000096:biosynthesis; D004789:Enzyme Activation / Q000187:drug effects; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007340:Insulinoma / Q000378:metabolism*; D007457:Iodine Radioisotopes; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D010451:Peptide PHI / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000502:physiology*; D018000:Receptors, Peptide; D014407:Tumor Cells, Cultured; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism / Q000494:pharmacology
chemical_list: D007328:Insulin; D007457:Iodine Radioisotopes; C042452:PHI peptide receptor; D010451:Peptide PHI; D011956:Receptors, Cell Surface; D018000:Receptors, Peptide; D014660:Vasoactive Intestinal Peptide; D000242:Cyclic AMP; D000262:Adenylyl Cyclases