Glucose induces oscillations of cytoplasmic Ca2+, Sr2+ and Ba2+ in pancreatic beta-cells without participation of the thapsigargin-sensitive store
1995 (English)In: Cell Calcium, Vol. 18, no 2, 165-173 p.Article in journal (Refereed) Published
Individual pancreatic beta -cells were used to study the glucose effects on the handling of Ca2+, Sr2+ and Ba2+. In extracellular medium containing one of these ions, single beta -cells responded to 11 mM glucose with large amplitude oscillations in cytoplasmic Ca2+, Sr2+ or Ba2+ with indistinguishable average frequencies (0.30-0.33/min). The oscillations disappeared after hyperpolarization with 400 microM diazoxide. Under such hyperpolarization, glucose stimulated the sequestration of Ca2+ and Sr2+ but not of repetitively mobilized by consecutive exposures to 100 microM carbachol. A 2-3 min exposure to 100 nM of the intracellular Ca(2+)-ATPase inhibitor thapsigargin also mobilized Ca2+ and Sr2+ and irreversibly abolished subsequent release by carbachol. However, thapsigargin did not prevent the large amplitude oscillations in Ca2+, Sr2+ or Ba2+ under non-hyperpolarizing conditions although the frequency of the Ca2+ oscillations was almost doubled. The results indicate that the slow oscillatory behavior of glucose-stimulated individual beta -cells does not depend on inositol 1,4,5-trisphosphate mediated release of intracellular Ca2+.
Place, publisher, year, edition, pages
1995. Vol. 18, no 2, 165-173 p.
Cell and Molecular Biology
IdentifiersURN: urn:nbn:se:uu:diva-52938PubMedID: 7585893OAI: oai:DiVA.org:uu-52938DiVA: diva2:80848