title: Islet endocrine-cell behavior from birth onward in mice with the nonobese diabetic genetic background.
abstract: BACKGROUND
  Glucagon-producing alpha cells play a crucial role during the perinatal period. Because of their peri-islet localization near the early dendritic and macrophage cell infiltration, we thought it pertinent to investigate alpha cells in greater depth in nonobese diabetic (NOD) mice, a well-recognized spontaneous model for human type I diabetes.
  
  
  METHODS
  We determined alpha-cell distribution (glucagon immunohistochemistry and image analysis) and activity (real-time reverse transcriptase polymerase chain reaction [RT-PCR] and glucagon radioimmunoassay [RIA]), in relationship to glycemia in NOD and lymphocyte-deficient NODscid mice as compared to control mice (C57BL/6) from birth onward.
  
  
  RESULTS
  NOD and NODscid mice, particularly at 1 day of age, had twice as many very small islets (<2,000 pixels) as C57BL/6 mice. During the postnatal period, the percentages of glucagon-positive areas in islets less than 2000 pixels were higher in NOD mice than C57BL/6; only a trend was found in NODscid. Pancreatic mRNA expression and glucagon content decreased in all strains at weaning. However, before weaning, pancreatic and blood glucagon levels were significantly lower in NOD and NODscid compared to C57BL/6 mice. Low basal nonfasting glycemia was observed in all strains before weaning with some strain differences: glycemia was significantly lower in NOD than C57BL/6, and higher in NODscid than NOD and C57BL/6.
  
  
  CONCLUSIONS
  These data suggest that, before weaning, NOD and, to some extent NODscid pancreata contain more immature islets (as reflected by their small size and high percentages of glucagon-positive areas, concomitant with lower glucagon storage and basal secretion) than C57BL/6 pancreata.
authors.affiliation: CNRS UMR 8603, University of Paris V, Necker Hospital, France.
authors.forename: C
authors.initials: C
authors.lastname: Pelegri
authors.forename: J G
authors.initials: JG
authors.lastname: Rosmalen
authors.forename: S
authors.initials: S
authors.lastname: Durant
authors.forename: M
authors.initials: M
authors.lastname: Throsby
authors.forename: V
authors.initials: V
authors.lastname: Alvès
authors.forename: J
authors.initials: J
authors.lastname: Coulaud
authors.forename: A
authors.initials: A
authors.lastname: Esling
authors.forename: J M
authors.initials: JM
authors.lastname: Pléau
authors.forename: H A
authors.initials: HA
authors.lastname: Drexhage
authors.forename: F
authors.initials: F
authors.lastname: Homo-Delarche
mesh_terms: D000375:Aging / Q000276:immunology; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003345:Corticosterone / Q000032:analysis; D003922:Diabetes Mellitus, Type 1 / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D005934:Glucagon / Q000276:immunology / Q000378:metabolism*; D007150:Immunohistochemistry; D007328:Insulin / Q000032:analysis; D007515:Islets of Langerhans / Q000502:physiology* / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011863:Radioimmunoassay; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014886:Weaning
chemical_list: D001786:Blood Glucose; D007328:Insulin; D012333:RNA, Messenger; D005934:Glucagon; D003345:Corticosterone