title: Evidence for the existence of CCK-producing cells in rat pancreatic islets.
abstract: BACKGROUND
  Although the existence of cholecystokinin-like immunoreactivity (CCK-LI) in rat pancreas had been reported previously, it was never clearly demonstrated whether CCK is produced in rat pancreatic islets.
  
  
  OBJECTIVE
  The purpose of this study was to elucidate the source of the CCK-LI, the molecular properties of CCK, and the expression of the CCK gene in islet cells.
  
  
  METHODS
  Immunohistochemical studies of rat pancreas were carried out with different rabbit antisera against CCK-8 and CCK-related peptide including N-terminal CCK-33 (1-22) and gastrin-17, and colocalization with known islet hormones including insulin, glucagon, somatostatin, and pancreatic polypeptide was investigated. The major molecular form of CCK in the islets was determined by HPLC. RT-PCR and in situ hybridization were performed to demonstrate the presence of the CCK transcript in the pancreas.
  
  
  RESULTS
  CCK-LI was found in the center of the islets, colocalized with insulin in B cells. The major molecular form of CCK in the islets was CCK-8. A 350-nucleotide fragment of PCR-amplified CCK cDNA was detected in the islet as well as the duodenum by RT-PCR. In situ hybridization showed that CCK messenger RNA was located in a large portion of the islets, and this was consistent with the immunohistochemical findings.
  
  
  CONCLUSIONS
  CCK messenger RNA and immunoreactivity are expressed in adult rat pancreatic islets, indicating that CCK-producing cells are present in adult rat islets.
authors.affiliation: Department of Gastroenterology, Tokyo Women's Medical College, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Shimizu
authors.forename: Y
authors.initials: Y
authors.lastname: Kato
authors.forename: K
authors.initials: K
authors.lastname: Shiratori
authors.forename: Y
authors.initials: Y
authors.lastname: Ding
authors.forename: Y
authors.initials: Y
authors.lastname: Song
authors.forename: R
authors.initials: R
authors.lastname: Furlanetto
authors.forename: T M
authors.initials: TM
authors.lastname: Chang
authors.forename: S
authors.initials: S
authors.lastname: Watanabe
authors.forename: N
authors.initials: N
authors.lastname: Hayashi
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
authors.forename: W Y
authors.initials: WY
authors.lastname: Chey
mesh_terms: D000818:Animals; D002766:Cholecystokinin / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D018076:DNA, Complementary / Q000032:analysis; D007150:Immunohistochemistry; D007328:Insulin / Q000032:analysis; D007515:Islets of Langerhans / Q000378:metabolism*; D008297:Male; D016133:Polymerase Chain Reaction; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018076:DNA, Complementary; D007328:Insulin; D002766:Cholecystokinin