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ATP-Sensitive K+ Channel Closure is not an Obligatory Step for Glucose-Induced Priming of Pancreatic B-Cell

  • N. Taguchi
  • T. Aizawa
  • K. Hashizume
Chapter
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 426)

Abstract

Exposure of the B-cell to high glucose has a priming effect so that insulin release in response to subsequent stimuli is enhanced1: the phenomenon is called “Time-Dependent Potentiation (TDP)”. For glucose-induced insulin release, closure of the ATP-sensitive K+ (K+ATP) channel is an obligatory step because all of the response is eliminated by the presence of diazoxide, an opener of the channel. However, we2 and others3 found that there is a K+ATP channel-independent branch of glucose-induced signaling in the B-cell, which is dependent on elevation of cytosolic Ca2+. Here, we show that “glucose-induced priming of the B-cell” and “glucose-induced insulin release by the B-cell” are mechanistically distinct from each other: closure of K+ATP channel is a pre-requisite for the latter but not for the former. Differential effects of lowering ambient Ca2+ concentration on glucose-induced TDP4,5 and glucose-induced insulin release were also evaluated.

Keywords

Insulin Release Initial Incubation Channel Closure Priming Period Subsequent Stimulus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Cerasi, E., 1975, Potentiation of insulin release by glucose in man. Quantitative analysis of the enhancement of glucose-induced insulin secretion by pretreatment with glucose in normal subjects, Acta Endocrinol. 79: 483–501.PubMedGoogle Scholar
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    Sato, Y., Aizawa, T., Komatsu, M., Okada, N., and Yamada, T., 1992, Dual functional role of membrane depolarization/Ca2+ influx in rat pancreatic B-cell, Diabetes 41: 438–443.PubMedCrossRefGoogle Scholar
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    Gembal, M., Gilon, P., and Henquin, J.-C., 1992, Evidence that glucose can control insulin release independently from its action on ATP-sensitive K+ channels in mouse B cells, J. Clin. Invest. 89: 1288–1295.PubMedCrossRefGoogle Scholar
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    Grill, V., Adamson, U., and Cerasi, E., 1978 Immediate and time dependent effects of glucose on insulin release from rat pancreatic tissue, J. Clin. Invest. 61: 1034–1043.PubMedCrossRefGoogle Scholar
  5. 5.
    Malaisse, W. J., and Sener, A., 1987 Interaction between D-glucose and Ca2+ in the priming of the pancreatic B-cell, Diabet. Res. 4: 5–8.Google Scholar

Copyright information

© Springer Science+Business Media New York 1997

Authors and Affiliations

  • N. Taguchi
    • 1
  • T. Aizawa
    • 1
  • K. Hashizume
    • 1
  1. 1.Shinshu University School of MedicineMatsumotoJapan

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