Pflügers Archiv

, Volume 378, Issue 2, pp 93–97 | Cite as

Effects of Na+, K+ and Mg2+ on45Ca2+ uptake by pancreatic islets

  • Bo Hellman
  • Janove Sehlin
  • Inge-Bert Täljedal
Transport Processes, Metabolism and Endocrinology; Kidney, Gastrointestinal Tract, and Exocrine Glands


Microdissected pancreatic islets of noninbredob/ob-mice were used to study ionic effects on the lanthanum-nondisplaceable45Ca2+ uptake by islet cells. Omission of Mg2+ from the incubation medium had no effect, but the45Ca2+ uptake was increased by omission of Na+ and decreased by omission of K+. Excess Mg2+ (1.2–15 mM) inhibited and excess K+ (4.7–25 mM) stimulated the45Ca2+ uptake in a concentration-dependent manner. Stimulation of45Ca2+ uptake in Na+-deficient islets was associated with an enhancement of the basal insulin release. Total abolishment of glucose-stimulated45Ca2+ uptake in K+-deficient islets did not preclude a significant secretory response to glucose. It is concluded that the lanthanum-nondisplaceable45Ca2+ uptake shows a partial correlation to insulin release.

Key words

Calcium uptake Insulin release Islets of Langerhans Lanthanum Magnesium Pancreatic islets Potassium Sodium 


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Copyright information

© Springer-Verlag 1978

Authors and Affiliations

  • Bo Hellman
    • 1
  • Janove Sehlin
    • 1
  • Inge-Bert Täljedal
    • 1
  1. 1.Department of HistologyUniversity of UmeaUmeå 6Sweden

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