Free and bound sodium in pancreatic beta-cells exposed to glucose and tolbutamide.
1989 (English)In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 164, no 1, 212-8 p.Article in journal (Refereed) Published
The effects of glucose and tolbutamide on the sodium handling of the pancreatic beta-cells were evaluated by measuring the total sodium content in intact islets from ob/ob-mice by integrating flame photometry and the free ion in individual beta-cells by dual wavelength fluorometry. Whereas increasing the glucose concentration from 3 to 20 mM resulted in a lowering of sodium, the addition of 100 microM tolbutamide caused a rise. The above-mentioned effects were most marked (about 50%) for the physiologically significant free sodium. The data indicate a more important role for Na+ in the regulation of insulin release than so far acknowledged. Increase of Na+ may contribute to the secretory response to hypoglycemic sulfonylureas by providing an additional rise of cytoplasmic Ca2+.
Place, publisher, year, edition, pages
1989. Vol. 164, no 1, 212-8 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-259872PubMedID: 2679551OAI: oai:DiVA.org:uu-259872DiVA: diva2:1061346