Transcellular transport in epithelial cell is a method for absorbing calcium from intestine to blood, providing effective mechanism of utilizing calcium at low calcium intake. In this study, we aimed at theoretically developing a simple mechanistic model explaining transcellular transport in calcium absorption process. Transcellular calcium transport was schematized into 3 steps which were entry, diffusion, and extrusion. Each step was separately modeled to include the specific feature of them. In detail, electro-diffusion, facilitated diffusion, and Michaelis-Menten kinetics were employed to model calcium entry, diffusion, and extrusion, respectively. Then, the developed models were numerically solved to find a solution which simultaneously satisfied 3 models under steady-state assumption. Result of model simulation was consistent with the known behavior of transcellular calcium absorption, showing that transcellular calcium transport became saturated with increase of luminal calcium concentration. Because transcellular calcium transport depends on calcium binding protein mediated by vitamin D we expect that this model can be used to find optimal regulatory point for increasing calcium absorption.

• Jae-Min Jung(Department of Biosystems Machinery Engineering, Chungnam National University)
• Dae-hyeon Byeon(Department of Biosystems Machinery Engineering, Chungnam National University)
• Wang-Hee Lee(Department of Biosystems Machinery Engineering, Chungnam National University)