Membrane potential and ion partitioning in an erythrocyte using the Poisson-Boltzmann equation.
In virtually all mammal cells, we can observe a much higher concentration of potassium ions inside the cell and vice versa for sodium ions. Classical theories ignore the specific ion effects and the difference in the thermodynamic reference states between intracellular and extracellular environments. Usually, this differential ion partitioning across a cell membrane is attributed exclusively to the active ion transport. Our aim is to investigate how much the dispersion forces contribute to active ion pumps in an erythrocyte (red blood cell) as well as the correction of chemical potential reference states between intracellular and extracellular environments. The ionic partition and the membrane potential in an erythrocyte are analyzed by the modified Poisson-Boltzmann equation, considering nonelectrostatic interactions between ions and macromolecules. Results show that the nonelectrostatic potential calculated by Lifshitz theory has only a small influence with respect to the high concentration of K(+) in the intracellular environment in comparison with Na(+).
†Programa de Pós-graduação em Engenharia Química, Universidade do Estado do Rio de Janeiro, 20550-013, Rio de Janeiro, Brazil.
Nathalia S V
NS
Barbosa
†Programa de Pós-graduação em Engenharia Química, Universidade do Estado do Rio de Janeiro, 20550-013, Rio de Janeiro, Brazil.
Eduardo R A
ER
Lima
‡Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1048, Blindern, NO-0316 Oslo, Norway.
Mathias
M
Boström
§Escola de Química, Universidade Federal do Rio de Janeiro, 21945-970, Rio de Janeiro, Brazil.|∥Programa de Engenharia Química, COPPE, Universidade Federal do Rio de Janeiro, 21945-970, Rio de Janeiro, Brazil.
Frederico W
FW
Tavares
D002712:Chlorides / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D004912:Erythrocytes / Q000502:physiology*; D006801:Humans; D015640:Ion Channel Gating / Q000502:physiology; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology*; D008954:Models, Biological; D011188:Potassium / Q000737:chemistry; D012964:Sodium / Q000737:chemistry
D002712:Chlorides; D007473:Ion Channels; D012964:Sodium; D011188:Potassium