Epithelial Fluid Transport is Due to Electro-osmosis (80%), Plus Osmosis (20%).

Epithelial fluid transport, an important physiological process shrouded in a long-standing enigma, may finally be moving closer to a solution. We propose that, for the corneal endothelium, relative proportions for the driving forces for fluid transport are 80% of paracellular electro-osmosis, and 20% classical transcellular osmosis. These operate in a cyclical process with a period of 9.

Net Fluorescein Flux Across Corneal Endothelium Strongly Suggests Fluid Transport is due to Electro-osmosis.

We have presented prior evidence suggesting that fluid transport results from electro-osmosis at the intercellular junctions of the corneal endothelium. Such phenomenon ought to drag other extracellular solutes. We have investigated this using fluorescein-Na2 as an extracellular marker.

[Ouabain switches Na+ transport to Na+/Na+ equivalent exchange in normal and apoptotic lymphoid cells].

A theory of change of the ionic fluxes in the lymphoid cells in their transition from normal to apoptosis, we have developed previously, is applied to the analysis of Na+/Na+ exchange fluxes in human lymphoid cells U937 exposed to ouabain. We solve a system of equations describing changes in the intracellular concentrations of Na+, K+ and Cl-, membrane potential and cell volume. It is shown that the Na+ input (I(Na/Na)) flux and output flux through the Na+/Na+ tract increased 4 times in 8 hours after disconnecting Na+/K+ -ATPase for normal cell U937.

[A new approach to the electrostatic stabilization of cations in the aqueous cavity of K+ channel: the role of nonlocal-electrostatic effects].

Methods of nonlocal electrostatics, applied to ion channels in our previous papers, are used to analyze the stability of K+ in the aqueous cavity of K+ channel. Other authors used formulas of classical electrostatics to calculate the energy of K+ in the aqueous cavity of KcsA. Using a new formulation of nonlocal-electrostatic theory, we obtained a formula for the image force energy acting on K+, which is in the center of a spherical cavity of K+ channel.

[On the theory of apoptotic decrease of the cell volume].

The dynamic model of membrane transport, which describes the changing of ion contents in the cell, cell volume and membrane potential, for the first time, is applied to analysis of the apoptotic processes. It is shown that increasing of permeability of K+, and Cl(-)-channels, decreasing of permeability of Na+ together with degradation of Na+/K+ pump, KCC and NC cotransporters lead to decreasing of cell U937 volume and plasma membrane depolarization at apoptosis induced by staurosporine in concentration 1 microM. The experimental data using at calculations was published in paper (Yurinskaya et al.