title: Small Mouse Islets Are Deficient in Glucagon-Producing Alpha Cells but Rich in Somatostatin-Secreting Delta Cells.
abstract: Small and big mouse islets were compared with special reference to their content of glucagon-producing α-cells and somatostatin-producing δ-cells. Areas stained for glucagon and somatostatin were measured in the largest cross section of small (diameter < 60 μm) and big (diameter > 100 μm) islets. Comparison of the areas indicated proportionally more δ- than α-cells in the small islets. After isolation with collagenase these islets were practically devoid of α-cells. We evaluated the functional importance of the islet size by measuring the Ca(2+) signal for insulin release. A majority of the small islets responded to the hyperpolarization action of somatostatin with periodic decrease of cytoplasmic Ca(2+) when glucose was elevated after tolbutamide blockade of the KATP channels.
authors: Department of Medical Cell Biology, Uppsala University, Box 571, 751 23 Uppsala, Sweden.
authors: Joey
authors: 0000-0002-8302-3253
authors: J
authors: Lau
authors: Department of Medical Cell Biology, Uppsala University, Box 571, 751 23 Uppsala, Sweden.
authors: Eva
authors: E
authors: Grapengiesser
authors: Department of Medical Cell Biology, Uppsala University, Box 571, 751 23 Uppsala, Sweden.
authors: Bo
authors: B
authors: Hellman
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects; D005934:Glucagon / Q000378:metabolism; D050416:Glucagon-Secreting Cells / Q000166:cytology* / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D009929:Organ Size; D013004:Somatostatin / Q000378:metabolism; D019864:Somatostatin-Secreting Cells / Q000166:cytology* / Q000378:metabolism; D014044:Tolbutamide / Q000494:pharmacology
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin; D013004:Somatostatin; D005934:Glucagon; D014044:Tolbutamide; D005947:Glucose