A kinetic model for the interaction of energy metabolism and osmotic states of human erythrocytes. Analysis of the stationary "in vivo" state and of time dependent variations under blood preservation conditions.

A model is presented which considers in a coherent way the energy metabolism, the membrane transport as well as the osmotic and electrostatic conditions of human erythrocytes. Particular attention is paid to the simulation of the system behaviour under blood preservation conditions as well as after transfusion of erythrocytes. The model considers the main glycolytic reactions, the active and passive transport of ions and the charges and osmotic actions of permeable and nonpermeable compounds. The glycolytic enzymes are characterized by realistic kinetic equations. Various non-stoichiometric regulatory couplings are taken into account. The passive transport of anions and cations is described by the Goldman-flux-equation. Mathematically, the system is described by 8 nonlinear differential equations for the concentrations of the glycolytic intermediates and ions, for the cell volume and the transmembrane potential. Further, various algebraic equations are taken into account which consider conservation conditions and equilibrium relations. The mathematical description is simplified by application of the quasi-steady state approximation. The model equations are solved for the stationary "in vivo" state and for the time dependent states observed during blood preservation and after transfusion. The theoretical results obtained by numerical integration are compared with experimental data. Conclusions are drawn with respect to the characterization of the recovery process of the energy metabolism and of the ionic states of erythrocytes after blood preservation and transfusion.