TO THE EDITOR: Nguyen and Kurtz (3) presented an equation expressing the concentration of sodium in plasma water, [Na ]pw (Eq. 11). They claim that “the new physiological insights provided by this model can for the first time provide a basis for understanding quantitatively how changes in the plasma protein concentration modulate the [Na ]pw”. An associated editorial heralds the equation as a m...

1. In order to complete the demonstration that the viscosity of suspensions of powdered gelatin in water is influenced by electrolytes in a similar way as the viscosity of solutions of gelatin, it is necessary to prove that the characteristic valency effect exists also in the case of the viscosity of suspended particles of solid gelatin in water. This proof is furnished in Fig. 1. 0.5 gm. of fi...

The fluorescence of the dye CC-6 [(3-hexyl-2-(3-hexyl-2-benzoxazolinylidene)-1-propenyl)-benzoxazolium iodide] has been shown to indicate Donnan potentials in rabbit skeletal muscle myofibrils. These results are in agreement with previously published work in which the potentials were measured with microelectrodes on glycerol-extraced muscle fibers. The magnitude of the Donnan potential of the m...

A comparison is made between the quantitative predictions of equilibrium ionic distribution in living cells according to the membrane theory (Donnan equilibrium) and according to the association-induction hypothesis. This comparison shows that both theories predict competitive effects of one permeant ion on the equilibrium concentration of another permeant ion; but within the limit of experimen...

The ideal Donnan potential of an ionized polyelectrolyte medium is shown to be an approximate solution to a system of Poisson-Boltzmann (PB) equations for a periodic array of charged plates in an electrolyte bath. This result, derived using homogenization and scaling methods, demonstrates that the macrocontinuum, thermodynamic Donnan, and statistical mechanical PB models describe the same pheno...

Membrane potentials of polysulfonated cation exchange membranes (unsupported polysulfone, SA3S and polyester supported polysulfone, SA3T) for KCl, NaCl and LiCl solutions using Ag/AgCl electrodes were measured. The measurements were carried out for, KCl SA3S or SA3T MCL, (M: K, Na and Li) systems. The concentration of salt (KCl) was kept constant in one side of the cell, C1, at 1.10 M was chang...

I t has been tacitly assumed by many investigators that the fluid formed by filtration through partially semipermeable membranes will be at diffusion equilibrium with the original fluid. In case one of the indiffusible constituents of the original fluid has an ion in common with a diffusible constituent, the so called Donnan membrane equilibrium would be set up if time adequate for the attainme...