Age-related immunohistochemical studies of A and D cells in pancreatic islets of C57BL/6J mice.
Sections of pancreatic islets from C57BL/6J mice aged 3, 14, and 24 months, consisting of islets derived from the dorsal primordium (DPI) and from the ventral primordium (VPI), were immunostained using the peroxidase-antiperoxidase (PAP) procedure for localization of glucagon (A cells) and somatostatin (D cells). The density (A or D cell area/islet area) of immunopositive cells were determined using computer-assisted image analysis. The density of A cells was significantly less in VPI of 14- and 24-month-old mice compared to 3-month-old mice. The density of A cells in 24 month DPI was less than 3 month DPI but no different from 14 month DPI. The mean area (microns 2) of A cells (only in DPI) was significantly less at 24 months compared to the 3 and 14 month groups. There were no differences in somatostatin staining when comparing the three age groups, although at all ages the density of D cells was always greater in the DPI. In conclusion, the major difference between the young and older mice was a deficiency of glucagon-stained cells in older mice. These results might be important in explaining improved glucose tolerance in aged C57BL/6J mice.
Slavin
B G
BG
Department of Anatomy and Cell Biology, School of Medicine, University of Southern California, Los Angeles 90033.
Lerner
S P
SP
D000375:Aging / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D005934:Glucagon / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D051379:Mice; D013004:Somatostatin / Q000378:metabolism
D013004:Somatostatin; D005934:Glucagon