Ca2+ oscillations in pancreatic islet cells secreting glucagon and somatostatin

Biochem Biophys Res Commun. 1995 Mar 17;208(2):644-9. doi: 10.1006/bbrc.1995.1387.

Abstract

Immunohistochemically identified glucagon-releasing alpha 2-cells from mouse pancreatic islets exhibited large amplitude oscillations of the cytoplasmic Ca2+ concentration in 3 mM glucose. Other small islet cells with similar oscillations in the presence of 20 mM glucose were identified as somatostatin-releasing alpha 1-cells. The oscillations in both cell types resembled those induced by glucose in the surrounding larger beta-cells in starting from the basal level and disappearing after addition of the voltage-dependent Ca2+ channel blocker methoxyverapamil. The discovery that the alpha 1- and alpha 2-cells have intrinsic abilities to generate oscillatory Ca2+ signals indicates that pulsatile release of somatostatin and glucagon do not require functional coupling to the beta-cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Gallopamil / pharmacology
  • Glucagon / metabolism*
  • Glucose / pharmacology
  • In Vitro Techniques
  • Islets of Langerhans / cytology
  • Islets of Langerhans / metabolism*
  • Mice
  • Periodicity
  • Somatostatin / metabolism*

Substances

  • Gallopamil
  • Somatostatin
  • Glucagon
  • Glucose
  • Calcium