Mathematical model for DO transport. (A) Model parameters used to estimate the DO profile through the tissue for mixed and static cases and 20% versus 2% pO2. (B) Schematic of model system (not to scale). (C) Predicted DO profiles through the tissue from the lumenal surface (Ri) to the ablumenal surface (Ro). Closed circles=mixed, 2% pO2. Open circles=mixed, 20% pO2. Closed triangles=static culture, 2% pO2. Open triangles=static culture, 20% pO2. DO, dissolved oxygen.