[Effect of operation of the Na, K-pump on the magnitude of cell membrane potentials and intracellular ion concentrations].

A model of the cell is considered under conditions of ionic current balance for basic potential-forming ions K+, Na+, Cl- and uniformity of intracellular volume. The volume of outer medium as compared to the cellular one is assumed as infinite. Passive movement of unidirectional ionic current in the model is determined by the concentration of this ion, membrane permeability for it and by the potential on the membrane. The electric field through the membrane is assumed constant. Na,K-pump is given by introducing membrane potential-independent component outward the ionic current for Na+/MNa+/ respectively and inward the ionic potential for K+/MK+/ ions respectively. It is assumed that the pump intensity is in direct proportion to the intracellular concentration of Na+ ions. The stechiometric coefficient during the pump work is given as a ratio MNa+/MK+. From the model analysis a graphic analysis of the cellular system is suggested. The latter is based on basis plane unambiguously given by outer concentrations of the ions and intracellular concentration of nonpenetrating ions. Such a basis plane reflects in terms of the model the multitude of the cellular system states. Each its point unambiguously determines intracellular concentrations of the ions, efficiency of the work of Na,K-pump and the ratio between the coefficients of ion permeability and the stechiometric coefficient of Na,K-pump.