Glucose-dependent alterations of intracellular free calcium by glucagon-like peptide-1(7-36amide) in individual ob/ob mouse beta-cells

Cell Calcium. 1994 May;15(5):391-400. doi: 10.1016/0143-4160(94)90014-0.


Depolarizing concentrations of glucose produce characteristic alterations of intracellular free Ca2+ ([Ca2+]i) in pancreatic beta-cells. The effects of the proposed incretin, glucagon-like peptide-1(7-36amide) (GLP-1a) on [Ca2+]i were determined from Fura-2 fluorescence ratio imaging of cultured ob/ob mouse pancreatic beta-cells. In control cells, [Ca2+]i is low in 3 mM glucose; increasing [glucose] to 8-12 mM results in an initial dip in [Ca2+]i followed by slow oscillating increases in [Ca2+]i. GLP-1a (0.03-10,000 pM) does not alter [Ca2+]i in 3 mM glucose, but does change the response to elevated glucose (8-12 mM). The time integral of the initial dip is reduced ([GLP-1a] 10-100 pM), and the integral of the [Ca2+]i signal is increased ([GLP-1a] > or = 1 pM). GLP-1a increases the frequency of sustained, stable plateau responses to elevated glucose, and the frequency of large, rapid spikes of increased [Ca2+]i associated with either plateaus, or oscillations. Application of a cAMP analog mimics most of the actions of GLP-1a. Activation of the GLP-1a receptor, or application of cAMP alters pancreatic beta-cell [Ca2+]i only when [glucose] is high.

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Cyclic AMP / analogs & derivatives
  • Diabetes Mellitus, Type 2 / metabolism*
  • Felodipine / pharmacology
  • Glucagon / pharmacology*
  • Glucagon-Like Peptide 1
  • Glucagon-Like Peptides
  • Glucose / pharmacology*
  • In Vitro Techniques
  • Islets of Langerhans / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Peptide Fragments / pharmacology


  • Peptide Fragments
  • glucagon-like peptide 1 (7-36)amide
  • Glucagon-Like Peptides
  • Glucagon-Like Peptide 1
  • Glucagon
  • Cyclic AMP
  • Glucose
  • Felodipine
  • Calcium