title: Characterisation of age-dependent beta cell dynamics in the male db/db mice.
abstract: OBJECTIVE
  To characterise changes in pancreatic beta cell mass during the development of diabetes in untreated male C57BLKS/J db/db mice.
  
  
  METHODS
  Blood samples were collected from a total of 72 untreated male db/db mice aged 5, 6, 8, 10, 12, 14, 18, 24 and 34 weeks, for measurement of terminal blood glucose, HbA1c, plasma insulin, and C-peptide. Pancreata were removed for quantification of beta cell mass, islet numbers as well as proliferation and apoptosis by immunohistochemistry and stereology.
  
  
  RESULTS
  Total pancreatic beta cell mass increased significantly from 2.1 ± 0.3 mg in mice aged 5 weeks to a peak value of 4.84 ± 0.26 mg (P < 0.05) in 12-week-old mice, then gradually decreased to 3.27 ± 0.44 mg in mice aged 34 weeks. Analysis of islets in the 5-, 10-, and 24-week age groups showed increased beta cell proliferation in the 10-week-old animals whereas a low proliferation is seen in older animals. The expansion in beta cell mass was driven by an increase in mean islet mass as the total number of islets was unchanged in the three groups.
  
  
  CONCLUSIONS
  The age-dependent beta cell dynamics in male db/db mice has been described from 5-34 weeks of age and at the same time alterations in insulin/glucose homeostasis were assessed. High beta cell proliferation and increased beta cell mass occur in young animals followed by a gradual decline characterised by a low beta cell proliferation in older animals. The expansion of beta cell mass was caused by an increase in mean islet mass and not islet number.
authors: Department of Histology, Gubra ApS, Hørsholm, Denmark.
authors: Louise S
authors: LS
authors: Dalbøge
authors: Dorthe L C
authors: DL
authors: Almholt
authors: Trine S R
authors: TS
authors: Neerup
authors: Efstathios
authors: E
authors: Vassiliadis
authors: Niels
authors: N
authors: Vrang
authors: Lars
authors: L
authors: Pedersen
authors: Keld
authors: K
authors: Fosgerau
authors: Jacob
authors: J
authors: Jelsing
mesh_terms: D000367:Age Factors; D000818:Animals; D017209:Apoptosis; D001786:Blood Glucose; D002096:C-Peptide / Q000097:blood; D049109:Cell Proliferation; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism; D004195:Disease Models, Animal; D005215:Fasting / Q000097:blood; D007328:Insulin / Q000097:blood; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D007515:Islets of Langerhans / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin