Figure 4.
Receptor dynamics and mass transport limitations introduce significant delay into calcium dynamics. Simulation of Eq. 1 only yields a very high and rapid transient. Dotted line, stimulus is a step increase in receptor activity. Solid line, simulation of Eqs. 1 and 6 coupled via the phosphoinositide pathway. Addition of receptor dynamics significantly attenuates and delays the transient. Broken line, stimulus as a step increase in cs. Simulation of Eqs. 1 and 6 coupled to thrombin balance in the perfusate further attenuates and delays the transient (cs = 1 unit per ml, c0 = 1 unit per ml, Caex = 0, τ = 0.1 N/m2).