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. 1985 Dec;48(6):919–930. doi: 10.1016/S0006-3495(85)83855-8

Effects of the calcium channel agonist, BAY K 8644, on electrical activity in mouse pancreatic B-cells.

P Lebrun, I Atwater
PMCID: PMC1329425  PMID: 2418891

Abstract

We studied the effects of the dihydropyridine derivative BAY K 8644 on the membrane potential of B-cells in mouse pancreatic islets. BAY K 8644, in a dose-dependent manner, decreased the spike frequency but increased the duration of the spikes elicited by glucose with or without quinine or tetraethylammonium (TEA). These effects were antagonized by cobalt and nifedipine but not by tetrodotoxin. The interval between spikes was proportionate to the duration of the spikes and the ratio of the interval to the spike duration was constant at all concentrations of BAY K 8644 tested. Peak inward current, estimated from the derivative of the action potential recorded in the presence of TEA, was increased by BAY K 8644 and decreased by nifedipine. BAY K 8644 elicited spike activity when the membrane was moderately depolarized by either 5.6 mM glucose or 15 mM K+, but did not change the membrane potential of the resting hyperpolarized B-cell. These results suggest that BAY K 8644 acts on the open Ca2+-channels. The threshold occurs at a membrane potential of -50 mV. Also, the modifications of the shape of the spikes appear to reflect specific changes in Ca2+ entry. We propose the existence of a Ca2+-induced Ca2+-channel inactivation process in the pancreatic B-cell.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Atwater I., Beigelman P. M. Dynamic characteristics of electrical activity in pancreatic beta-cells. I. - Effects of calcium and magnesium removal. J Physiol (Paris) 1976 Nov;72(6):769–786. [PubMed] [Google Scholar]
  2. Atwater I., Dawson C. M., Eddlestone G. T., Rojas E. Voltage noise measurements across the pancreatic beta-cell membrane: calcium channel characteristics. J Physiol. 1981 May;314:195–212. doi: 10.1113/jphysiol.1981.sp013701. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Atwater I., Dawson C. M., Ribalet B., Rojas E. Potassium permeability activated by intracellular calcium ion concentration in the pancreatic beta-cell. J Physiol. 1979 Mar;288:575–588. [PMC free article] [PubMed] [Google Scholar]
  4. Atwater I., Dawson C. M., Scott A., Eddlestone G., Rojas E. The nature of the oscillatory behaviour in electrical activity from pancreatic beta-cell. Horm Metab Res Suppl. 1980;Suppl 10:100–107. [PubMed] [Google Scholar]
  5. Atwater I., Ribalet B., Rojas E. Mouse pancreatic beta-cells: tetraethylammonium blockage of the potassium permeability increase induced by depolarization. J Physiol. 1979 Mar;288:561–574. [PMC free article] [PubMed] [Google Scholar]
  6. Brown A. M., Kunze D. L., Yatani A. The agonist effect of dihydropyridines on Ca channels. Nature. 1984 Oct 11;311(5986):570–572. doi: 10.1038/311570a0. [DOI] [PubMed] [Google Scholar]
  7. Dawson C. M., Atwater I., Rojas E. The response of pancreatic beta-cell membrane potential to potassium-induced calcium influx in the presence of glucose. Q J Exp Physiol. 1984 Oct;69(4):819–830. doi: 10.1113/expphysiol.1984.sp002871. [DOI] [PubMed] [Google Scholar]
  8. Enyeart J. J., Hinkle P. M. The calcium agonist Bay K 8644 stimulates secretion from a pituitary cell line. Biochem Biophys Res Commun. 1984 Aug 16;122(3):991–996. doi: 10.1016/0006-291x(84)91189-6. [DOI] [PubMed] [Google Scholar]
  9. García A. G., Sala F., Reig J. A., Viniegra S., Frías J., Fontériz R., Gandía L. Dihydropyridine BAY-K-8644 activates chromaffin cell calcium channels. Nature. 1984 May 3;309(5963):69–71. doi: 10.1038/309069a0. [DOI] [PubMed] [Google Scholar]
  10. Hagiwara S., Byerly L. Calcium channel. Annu Rev Neurosci. 1981;4:69–125. doi: 10.1146/annurev.ne.04.030181.000441. [DOI] [PubMed] [Google Scholar]
  11. Hess P., Lansman J. B., Tsien R. W. Different modes of Ca channel gating behaviour favoured by dihydropyridine Ca agonists and antagonists. Nature. 1984 Oct 11;311(5986):538–544. doi: 10.1038/311538a0. [DOI] [PubMed] [Google Scholar]
  12. Kojima K., Kojima I., Rasmussen H. Dihydropyridine calcium agonist and antagonist effects on aldosterone secretion. Am J Physiol. 1984 Nov;247(5 Pt 1):E645–E650. doi: 10.1152/ajpendo.1984.247.5.E645. [DOI] [PubMed] [Google Scholar]
  13. Kokubun S., Reuter H. Dihydropyridine derivatives prolong the open state of Ca channels in cultured cardiac cells. Proc Natl Acad Sci U S A. 1984 Aug;81(15):4824–4827. doi: 10.1073/pnas.81.15.4824. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Malaisse-Lagae F., Mathias P. C., Malaisse W. J. Gating and blocking of calcium channels by dihydropyridines in the pancreatic B-cell. Biochem Biophys Res Commun. 1984 Sep 28;123(3):1062–1068. doi: 10.1016/s0006-291x(84)80241-7. [DOI] [PubMed] [Google Scholar]
  15. Malaisse W. J., Boschero A. C. Calcium antagonists and islet function. XI. Effect of nifedipine. Horm Res. 1977;8(4):203–209. doi: 10.1159/000178801. [DOI] [PubMed] [Google Scholar]
  16. Meissner H. P. Electrical characteristics of the beta-cells in pancreatic islets. J Physiol (Paris) 1976 Nov;72(6):757–767. [PubMed] [Google Scholar]
  17. Plant T. D., Standen N. B., Ward T. A. The effects of injection of calcium ions and calcium chelators on calcium channel inactivation in Helix neurones. J Physiol. 1983 Jan;334:189–212. doi: 10.1113/jphysiol.1983.sp014489. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Renaud J. F., Méaux J. P., Romey G., Schmid A., Lazdunski M. Activation of the voltage-dependent Ca2+ channel in rat heart cells by dihydropyridine derivatives. Biochem Biophys Res Commun. 1984 Nov 30;125(1):405–412. doi: 10.1016/s0006-291x(84)80382-4. [DOI] [PubMed] [Google Scholar]
  19. Ribalet B., Beigelman P. M. Calcium action potentials and potassium permeability activation in pancreatic beta-cells. Am J Physiol. 1980 Sep;239(3):C124–C133. doi: 10.1152/ajpcell.1980.239.3.C124. [DOI] [PubMed] [Google Scholar]
  20. Ribalet B., Beigelman P. M. Effects of divalent cations on beta-cell electrical activity. Am J Physiol. 1981 Jul;241(1):C59–C67. doi: 10.1152/ajpcell.1981.241.1.C59. [DOI] [PubMed] [Google Scholar]
  21. Schramm M., Thomas G., Towart R., Franckowiak G. Novel dihydropyridines with positive inotropic action through activation of Ca2+ channels. Nature. 1983 Jun 9;303(5917):535–537. doi: 10.1038/303535a0. [DOI] [PubMed] [Google Scholar]
  22. Wollheim C. B., Sharp G. W. Regulation of insulin release by calcium. Physiol Rev. 1981 Oct;61(4):914–973. doi: 10.1152/physrev.1981.61.4.914. [DOI] [PubMed] [Google Scholar]

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