Figure 2. Simulation of cytosolic Ca²⁺ oscillations in a pancreatic acinar cell during gradual store depletion.

The gradual depletion of the Ca²⁺ store in the model was achieved by the extrusion of cytosolic Ca²⁺ by PMCA and the lack of compensating Ca²⁺ influx through the plasma membrane. (A) [Ca²⁺]_c (lower trace) and [Ca²⁺]_ER (upper trace) during the simulation. At the resting condition [Ca²⁺]_c=0.08 μM and [Ca²⁺]_ER=200 μM. The cell was stimulated by increasing [IP₃] from 0 to 0.254 μM. (B) The rise time (•) and the decay time (○) of cytosolic Ca²⁺ spikes during the simulation.