title: Heterogeneous cell renewal of pancreas in mice: [(3)H]-thymidine autoradiographic investigation.
abstract: BACKGROUND
  Although cell kinetics of the gastrointestinal mucosa has been extensively examined, that of the pancreas has not been fully analyzed.
  
  
  OBJECTIVE
  To determine the renewal rate of pancreatic cells directly.
  
  
  METHODS
  Postnatal proliferative activity and cellular renewal of the parenchymal cells in ICR mouse pancreas were studied by immunohistochemistry and [(3)H]-thymidine autoradiography.
  
  
  RESULTS
  In the single labeling experiments, the proliferative activity of the parenchymal cells in pancreas showed peaks at a few days after birth, decreased thereafter, and reached a low level at 2 months after birth. Continuous labeling experiments revealed that, in the adult pancreas, the half lives of acinar cells, islet cells, and duct epithelial cells were approximately 70 days, 47 days, and 40 days, respectively. Moreover, in the exocrine pancreas, acinar cells of the peri-insular region proliferated more actively than those of the tele-insular region. The renewal rate of glucagon cells was more rapid than that of insulin cells or somatostatin cells. Large ducts showed a high rate of cell renewal in comparison with small ducts.
  
  
  CONCLUSIONS
  The results of this study indicate that cell renewal rates of the pancreas are not homogeneous, but heterogeneous.
authors.affiliation: Fourth Department of Internal Medicine, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan. magami@tokyo-med.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Magami
authors.forename: Takeshi
authors.initials: T
authors.lastname: Azuma
authors.forename: Hideto
authors.initials: H
authors.lastname: Inokuchi
authors.forename: Fuminori
authors.initials: F
authors.lastname: Moriyasu
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kawai
authors.forename: Takanori
authors.initials: T
authors.lastname: Hattori
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001345:Autoradiography; D002455:Cell Division / Q000502:physiology; D007515:Islets of Langerhans / Q000166:cytology* / Q000254:growth & development; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010179:Pancreas / Q000166:cytology* / Q000254:growth & development; D013936:Thymidine / Q000493:pharmacokinetics; D014316:Tritium
chemical_list: D014316:Tritium; D013936:Thymidine