Glucose-induced reduction of the sodium content in beta-cell-rich pancreatic islets.
The sodium contents of beta-cell-rich pancreatic islets from ob/ob-mice were measured with an integrating flame photometer. After washing to an apparent steady state with different types of ice-cold media, islets incubated in the absence of glucose contained 79-108 mmol sodium kg-1 dry weight. Exposure to glucose resulted in 25% reduction of the islet content of sodium. This effect became manifest in the presence of 5 mM glucose, there being no additional reduction with a further increase of glucose to 20 mM. Depression of Na+ activity may partially explain why glucose, under certain conditions, can lower cytoplasmic Ca2+ and even inhibit insulin release.
D000818:Animals; D002118:Calcium / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology*; D007424:Intracellular Fluid / Q000032:analysis; D007515:Islets of Langerhans / Q000032:analysis / Q000187:drug effects*; D051379:Mice; D008820:Mice, Obese / Q000378:metabolism; D012964:Sodium / Q000032:analysis*
D012964:Sodium; D005947:Glucose; D002118:Calcium