Simulation of passive-gradient models.

Fig 8A: Simulated ferrous iron flux using passive-gradient SD model for the four extracellular medium conditions. Absolute values of simulated ferrous iron flux for passive-gradient model with addition of Cp (300 µg/ml), apo-Tf (55 µM) or apo-Tf + Cp in extracellular medium under hypoxic conditions (1% O₂). Simulations show no flux change relative to control with addition of Cp, apo-Tf, or apo-Tf + Cp after 1, 5 or 10 min. Simulated flux dynamics decrease to the same extent with time for all four experimental conditions of extracellular medium. Fig 8B: Dynamic normalized % iron release from passive-gradient models. The output from both SL and SD models overlap with control. The passive-gradient models cannot simulate the enhanced iron release in the presence of Cp, apo-Tf and both.