Assessment of pancreatic islet-cell population in the hyperglycemic athymic nude mouse: immunohistochemical, ultrastructural, and hormonal studies.
Previous studies in diabetic animal models have demonstrated altered pancreatic islet-cell populations. To further characterize the diabetic syndrome in our athymic nude mouse colony, we studied the population of endocrine cells in pancreatic islets of 4-week-old normoglycemic and 8-week-old hyperglycemic athymic nude (nu/nu) mice using immunohistochemistry, morphometry, and electron microscopy. In normoglycemic 4-week athymic nu/nu mice, the proportions of B (insulin-secreting) cells and A (glucagon-secreting) cells were similar to those in control Balb/c mice; however, the D (somatostatin-secreting) cells were significantly decreased in nu/nu mice. The populations of B and A cells appeared to be normal in hyperglycemic 8-week-old nu/nu mice while there was a significant increase in the proportion of D cells when compared with the proportion in Balb/c mice. Electron microscopic studies indicated that the appearance of B and A cells was similar in the 8-week-old hyperglycemic nu/nu and in controls; however, the D cells appeared to be enlarged and were finely packed with electron-dense secretory granules. Radioimmunoassays of the pancreatic content (micrograms/g fresh pancreas) of insulin, glucagon, and somatostatin in pancreata in 8-week-old normal Balb/c and hyperglycemic athymic nude mice were similar; however, the somatostatin content was significantly increased in the 8-week-old hyperglycemic nu/nu mice compared with age and sex-matched controls. These results demonstrate an altered D cell population and an increase in somatostatin levels in the pancreatic islets of the hyperglycemic athymic nude mouse animal model.(ABSTRACT TRUNCATED AT 250 WORDS)
Zeidler
A
A
Department of Medicine, University of Southern California, School of Medicine, Los Angeles.
Arbuckle
S
S
Mahan
E
E
Soejima
K
K
Slavin
B G
BG
Albrecht
G H
GH
Goldman
J
J
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002452:Cell Count; D005934:Glucagon / Q000097:blood; D005951:Glucose Tolerance Test; D006943:Hyperglycemia / Q000276:immunology / Q000503:physiopathology*; D007328:Insulin / Q000097:blood; D007515:Islets of Langerhans / Q000276:immunology / Q000503:physiopathology* / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008854:Microscopy, Electron; D011863:Radioimmunoassay; D013004:Somatostatin / Q000097:blood
D001786:Blood Glucose; D007328:Insulin; D013004:Somatostatin; D005934:Glucagon