Model dynamics with FT core iron release.

Release was incorporated into the model and balanced by expression as noted above to reach an equilibrium FT concentration of 5nM. The model was then run for 10,000 seconds to let the system approach steady state (where LIP did not change over time). Then LIP was doubled and subsequently halved (at time 25,000). a. The amount of LIP (blue), core (green), DFP (orange) and FT-cage (red) concentrations are plotted over time. For analyzing behavior over the long term and response to repeated iron challenges (b—e), three increasing expression rate values (3.075x10-14, 6.015x10-14, 1.203x10-13) were chosen for the long term sequestration analysis (“low”, “mid”, “high” curve labels respectively). These rates corresponded to equilibrium concentrations of FT of 2.56nM, 5nM, and 10nM. For simulation every 105 s (about 1 day) the LIP was increased by 0.5μM, a small physiologic dose. The b) LIP and c) APC were plotted corresponding to the model with each of these expression rate values over time. The reverse was also performed, where every 105 s the LIP was reduced to 0 and again the d) LIP and e) APC were plotted.