Mathematical modelling of stimulus-secretion coupling in the pancreatic B-cell. I. Dynamics of insulin release.
A mathematical model for cyclic AMP-Ca2+ interactions in pancreatic islets, defined in a previous study, was modified to include two new features. First, the cytosol and vacuolar Ca2+ pools were stratified in a cortical layer (representing 1 to 20% of the total cellular pool) and central core. Second, the changes in Ca2+ inflow and Ca2+ fractional outflow rate evoked by a rise in glucose concentration were discontinued during the 3rd and 4th min of stimulation. In this onion leaf sheet model, the biphasic pattern of glucose-induced insulin release could be simulated. This new model emphasizes the significance of both cytosol heterogeneity and signal discontinuity in the dynamics of insulin secretion.
D000818:Animals; D002118:Calcium / Q000502:physiology*; D000242:Cyclic AMP / Q000502:physiology*; D003600:Cytosol / Q000378:metabolism; D005947:Glucose / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000378:metabolism*; D008433:Mathematics; D008954:Models, Biological
D007328:Insulin; D000242:Cyclic AMP; D005947:Glucose; D002118:Calcium