title: Characterization of Insulin-Immunoreactive Cells and Endocrine Cells Within the Duct System of the Adult Human Pancreas.
abstract: OBJECTIVE
  The adult pancreatic duct system accommodates endocrine cells that have the potential to produce insulin. Here we report the characterization and distribution of insulin-immunoreactive cells and endocrine cells within the ductal units of adult human pancreas.
  
  
  METHODS
  Sequential pancreas sections from 12 nondiabetic adults were stained with biomarkers of ductal epithelial cells (cytokeratin 19), acinar cells (amylase), endocrine cells (chromogranin A; neuron-specific enolase), islet hormones (insulin, glucagon, somatostatin, pancreatic polypeptide), cell proliferation (Ki-67), and neogenesis (CD29).
  
  
  RESULTS
  The number of islet hormone-immunoreactive cells increased from large ducts to the terminal branches. The insulin-producing cells outnumbered endocrine cells reactive for glucagon, somatostatin, or pancreatic polypeptide. The proportions of insulin-immunoreactive count compared with local islets (100% as a baseline) were 1.5% for the main ducts, 7.2% for interlobular ducts, 24.8% for intralobular ducts, 67.9% for intercalated ducts, and 348.9% for centroacinar cells. Both Ki-67- and CD29-labeled cells were predominantly localized in the terminal branches around the islets. The terminal branches also showed cells coexpressing islet hormones and cytokeratin 19.
  
  
  CONCLUSIONS
  The adult human pancreatic ducts showed islet hormone-producing cells. The insulin-reactive cells predominantly localized in terminal branches where they may retain potential capability for β-cell neogenesis.
authors.affiliation: From the *Center for Diabetic Systems Medicine, Faculty of Basic Medicine, Guilin Medical University, Guilin; and †Molecular Endocrinology and Toxicology Laboratory, Department of Biology, Hong Kong Baptist University, Hong Kong, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Li
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Zhang
authors.forename: Lan
authors.initials: L
authors.lastname: Yu
authors.forename: Xia
authors.initials: X
authors.lastname: Zou
authors.forename: Hailu
authors.initials: H
authors.lastname: Zhao
mesh_terms: D000328:Adult; D000681:Amylases / Q000378:metabolism; D001344:Autopsy; D015415:Biomarkers / Q000378:metabolism; D053379:Chromogranin A / Q000378:metabolism; D055098:Endocrine Cells / Q000378:metabolism*; D005260:Female; D005934:Glucagon / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D019012:Integrin beta1 / Q000378:metabolism; D053539:Keratin-19 / Q000378:metabolism; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D010179:Pancreas / Q000166:cytology / Q000378:metabolism*; D010183:Pancreatic Ducts / Q000166:cytology / Q000378:metabolism*; D010191:Pancreatic Polypeptide / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D013004:Somatostatin / Q000378:metabolism
chemical_list: D015415:Biomarkers; D053379:Chromogranin A; D007328:Insulin; D019012:Integrin beta1; D053539:Keratin-19; D019394:Ki-67 Antigen; D013004:Somatostatin; D010191:Pancreatic Polypeptide; D005934:Glucagon; D000681:Amylases; D010751:Phosphopyruvate Hydratase