Mathematical Model to Study IP3 Dynamics Dependent Calcium Oscillations in Pancreatic Acinar Cells

Complex calcium oscillations in the cytosol are systematically investigated through the mathematical model based approach. This model is proposed to illustrate the mechanism of Ca2+ induced Ca2+ release (CICR), taking into account the activation of both the inositol-trisphosphate receptors (IPR), and the Ryanodine receptors (RyR). The production of intracellular (1,4,5) Inositol trisphosphate [IP3] via the production of phospholipase C isoform by calcium, and [IP3] degradation by phosphorylation by IP3 kinase (i.e., IP3K) via calcium is considered in the model. The recent study has shown that IP3 level oscillates together with the intracellular calcium concentration [Ca2+]. Thus, in this paper a possible mechanism is presented through which Ca2+ oscillates with IP3 oscillations. The bifurcation analysis is performed to explore the different dynamic behaviors of the model, and obtained the sinusoidal to raised-baseline spikes, sustained oscillations, and low to high frequency oscillations.