Stationary-state sodium and potassium ion distributions of human erythrocytes

Publisher Website
Google Scholar
Abstract
A general theory of material transfer through biological barriers based on the principles of irreversible thermodynamics predicts that stationary-state intracellular-extracellular ratios of permeable ions are exponentially related to steady-state flows of metabolites across the cell boundary (Nims, Am. J. Physiol. 201: 987, 1961). This prediction was tested using a red cell-plasma system in which stationary-state distributions of sodium and potassium were related to steady-state flows of lactic acid. The ion distributions were measured over a wide range of metabolic flows obtained by altering the incubating temperature. Within the limits of experimental error the predicted relationship was followed. M in (NapKc/KacKp) = MnL/T is a summation of independent membrane parameters and frietional coefficients, nL is the transmembrane flow rate of lactic acid, T is temperature, and p and c refer to the plasma and cellular phases. It is concluded that the above relation provides an acceptable thermodynamic explanation of nonequilibrium sodium and potassium distributions across the human erythrocyte cell boundary.