Mathematical modeling of acid-base physiology

Area of Science:

• Physiology
• Biophysics
• Computational Biology

Background:

• Cellular and organismal pH homeostasis is crucial for all biological functions.
• Intracellular pH (pHi) and extracellular pH (pHo) regulation involves complex interactions of transporters, passive fluxes, and buffer systems.
• Understanding these intricate acid-base dynamics necessitates quantitative modeling.

Purpose of the Study:

• To summarize existing mathematical models for acid-base movements.
• To introduce a novel mathematical model for simulating pHi and pHo changes in a spherical cell.
• To explore the impact of simultaneous CO2 and HCO3(-) influx on cellular pH.

Main Methods:

• Review of existing mathematical models for acid-base dynamics.
• Development of a new mathematical model for a spherical cell capable of handling multiple buffer reactions.
• Simulation of pH changes in Xenopus oocytes due to transmembrane acid-base equivalent transport.

Main Results:

• The developed model accurately simulates pHi and pHo changes.
• The model accounts for complex interactions between transport, diffusion, and buffering.
• Initial simulations explored the effects of simultaneous CO2 and HCO3(-) influx.

Conclusions:

• Mathematical modeling is essential for understanding complex acid-base regulation.
• The novel model provides a powerful tool for simulating cellular pH dynamics.
• Future models can be extended to various cell types and tissues for whole-body pH homeostasis research.