Why pancreatic islets burst but single β cells do not

The heterogeneity hypothesis

P. Smolen, J. Rinzel, A. Sherman

Research output: Contribution to journalArticle

Abstract

Previous mathematical modeling of β cell electrical activity has involved single cells or, recently, clusters of identical cells. Here we model clusters of heterogeneous cells that differ in size, channel density, and other parameters. We use gap-junctional electrical coupling, with conductances determined by an experimental histogram. We find that, for reasonable parameter distributions, only a small proportion of isolated β cells will burst when uncoupled, at any given value of a glucose-sensing parameter. However, a coupled, heterogeneous cluster of such cells, if sufficiently large (~125 cells), will burst synchronously. Small clusters of such cells will burst only with low probability. In large clusters, the dynamics of intracellular calcium compare well with experiments. Also, these clusters possess a dose-response curve of increasing average electrical activity with respect to a glucose-sensing parameter that is sharp when the cluster is coupled, but shallow when the cluster is decoupled into individual cells. This is in agreement with comparative experiments on cells in suspension and islets.

Original languageEnglish (US)
Pages (from-to)1668-1680
Number of pages13
JournalBiophysical Journal
Volume64
Issue number6
StatePublished - 1993

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Islets of Langerhans
Glucose
Suspensions
Calcium

ASJC Scopus subject areas

  • Biophysics

Cite this

Why pancreatic islets burst but single β cells do not : The heterogeneity hypothesis. / Smolen, P.; Rinzel, J.; Sherman, A.

In: Biophysical Journal, Vol. 64, No. 6, 1993, p. 1668-1680.

Research output: Contribution to journalArticle

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