Skip to main content
SpringerLink
Log in

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

  • Transport Processes, Metabolism and Endocrinology; Kidney, Gastrointestinal Tract, and Exocrine Glands
  • Published:
Pflügers Archiv Aims and scope Submit manuscript

Abstract

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.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Gagerman, E., Idahl, L.-Å., Meissner, H. P., Täljedal, I.-B.: Insulin release. cGMP, cAMP and membrane potential in acetyl-choline-stimulated islets. Am. J. Physiol. (in press)

  2. Hellman, B.: Calcium and pancreatic β-cell function. 3. Validity of the La3-wash technique for discriminating between superficial and intracellular45Ca. Biochim. Biophys. Acta540, 534–542 (1978)

    Google Scholar 

  3. Hellman, B., Idahl, L.-Å., Lernmark Å., Sehlin, J., Täljedal, I.-B.: The pancreatic β-cell recognition of insulin secretagogues. Effects of calcium and sodium on glucose metabolism and insulin release. Biochem. J.138, 33–45 (1974)

    Google Scholar 

  4. Hellman, B., Idahl, L.-Å., Lenzen, S., Sehlin, J., Täljedal, I.-B.: Further studies on the relationship between insulin release and lanthanum-nondisplaceable45Ca2+ uptake by pancreatic islets: effects of fructose and starvation. Endocrinology102, 1856–1863 (1978)

    Google Scholar 

  5. Hellman, B., Lenzen, S., Sehlin, J., Täljedal, I.-B.: Effects of various modifiers of insulin release on the lanthanumnondisplaceable45Ca2+ uptake by isolated pancreatic islets. Diabetologia13, 49–53 (1977)

    Google Scholar 

  6. Hellman, B., Sehlin, J., Täljedal, I.-B.: Effects of glucose on45Ca2+ uptake by pancreatic islets as studied with the lanthanum method. J. Physiol. (Lond.)254, 639–656 (1976)

    Google Scholar 

  7. Hellman, B., Sehlin, J., Täljedal, I.-B.: Calcium and secretion: distinction between two pools of glucose-sensitive calcium in pancreatic islets. Science194, 1421–1423 (1976)

    Google Scholar 

  8. Henquin, J.-C., Lambert, A. E.: Cationic environment and dynamics of insulin secretion. II. Effect of a high concentration of potassium. Diabetes23, 933–942 (1974)

    Google Scholar 

  9. Henquin, J.-C., Lambert, A. E.: Cationic environment and dynamics of insulin secretion. III. Effect of the absence of potassium. Diabetologia10, 789–794 (1974)

    Google Scholar 

  10. Henquin, J.-C., Lambert, A. E.: Cobalt inhibition of insulin secretion and calcium uptake by isolated rat islets. Am. J. Physiol.228, 1669–1677 (1975)

    Google Scholar 

  11. Lambert, A. E.: The regulation of insulin secretion. Rev. Physiol. Biochem. Pharmacol.75, 97–159 (1976)

    Google Scholar 

  12. Malaisse, W. J.: Role of cations. In: Insulin II. Handbook of exp. pharmacol 32/2 (Hasselblatt, A., v. Bruchhausen, F., eds.), pp. 145–155. Berlin-Heidelberg-New York: Springer 1975

    Google Scholar 

  13. Malaisse,-Lage, F., Malaisse, W. J.: Stimulus-secretion coupling of glucose-induced insulin release. III. Uptake of45calcium by isolated islets of Langerhans. Endocrinology88, 72–80 (1971)

    Google Scholar 

  14. Milner, R. D. G., Hales, C. N.: The role of calcium and magnesium in insulin secretion from rabbit pancreas studied in vitro. Diabetologia3, 47–49 (1967)

    Google Scholar 

  15. Milner, R. D. G., Hales, C. N.: Ionic mechanisms in the regulation of insulin secretion. In: The Structure and Metabolism of the Pancreatic Islets (Falkmer, S., Hellman, B., Täljedal, I.-B., eds.), pp. 489–493. Oxford: Pergamon Press 1970

    Google Scholar 

  16. Naber, S. P., McDaniel, M. L., Lacy, P. E.: The effect of glucose on the acute uptake and efflux of calcium-45 in isolated rat islets. Endocrinology101, 686–693 (1977)

    Google Scholar 

  17. Täljedal, I.-B.: Chlorotetracycline as a fluorescent Ca2+ probe in pancreatic islet cells. J. Cell Biol.76, 652–674 (1978)

    Google Scholar 

Download references

Author information

Author notes

  1. Bo Hellman

    Present address: Department of Histology, Biomedicum, University of Uppsala, S-75123, Uppsala, Sweden

Authors and Affiliations

  1. Department of Histology, University of Umea, Umeå 6, Sweden

    Bo Hellman, Janove Sehlin & Inge-Bert Täljedal

Authors
  1. Bo Hellman
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Janove Sehlin
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Inge-Bert Täljedal
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Hellman, B., Sehlin, J. & Täljedal, IB. Effects of Na+, K+ and Mg2+ on45Ca2+ uptake by pancreatic islets. Pflugers Arch. 378, 93–97 (1978). https://doi.org/10.1007/BF00584440

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00584440

Key words

Search

Navigation