Hypoxia modeling using Luo-Rudy II cell model

This study is aimed to present the development phases of hypoxia and anoxia using the dynamic Luo-Rudy II (LR) ventricular cell model. This task involves the robustness analysis of the selected cell model in low oxygen level circumstances that alter the ionic conductance properties of the cellular membrane and partially or totally inhibit the ionic pump functionality. We investigated hypoxia and its effect on activation potential, ionic currents, pumps, exchangers, and ionic concentrations involved in the LR model. To simulate non-pathologic cases we used Na⁺ 132-148 mmol/L, K⁺ 3.5-5 mmol/L, Ca²⁺ 2 mmol/L extra-cellular and Na⁺ 8-11.4 mmol/L, K⁺ 130-175 mmol/L, Ca²⁺ 0.11-0.16 μmol/L intra-cellular ionic concentrations. The presence of hypoxia has reduced the ionic pump functionality. Decreasing ionic pump power for 2-minute duration by 10%, 25%, 40%, 60%, 75%, respectively, caused a reduction of sodium ionic gradients by 1%, 3%, 7%, 14%, 19%, potassium ionic gradients by 2%, 5%, 10%, 17%, 23%, and calcium ionic gradient by 6%, 14%, 22%, 32%, 46%, respectively. The calcium regulation mechanism is more sensitive to hypoxia than the potassium regulation, while the sodium regulation is the most robust among the investigated pump functionalities.