Glucose-induced buffering of cytoplasmic Ca2+ in the pancreatic beta-cell--an artifact or a physiological phenomenon?

Biochem Biophys Res Commun. 1989 Mar 31;159(3):907-12. doi: 10.1016/0006-291x(89)92194-3.


The effects of stimulated metabolism on the cytoplasmic Ca2+ concentration (Ca2+i) of insulin-releasing pancreatic beta-cells were studied. When the glucose concentration was increased from 5 to 20 mM, some cell preparations responded with initial lowering of Ca2+i followed by a rise, whereas Ca2+i only increased in others. After prolonged exposure to 5 or 10 mM of the sugar, depolarization with high concentrations of sulfonylurea or K+ caused rapid increases of Ca2+i. However, when subsequently raising glucose to 20 mM there were pronounced temporary decreases of Ca2+i. Marked Ca2+i reducing effects were also obtained after prolonged exposure to 20 mM glucose, when metabolism was augmented further by exposure to leucine or beta-2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid. The results indicate that buffering of Ca2+i is not an artifact but may have physiological significance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Cytosol / drug effects
  • Cytosol / metabolism
  • Glucose / pharmacology*
  • Islets of Langerhans / drug effects
  • Islets of Langerhans / metabolism*
  • Kinetics
  • Leucine / pharmacology
  • Mice
  • Mice, Obese


  • Leucine
  • Glucose
  • Calcium