The presence of negatively charged, impermeant proteins in the plasma space alters the distribution of diffusible ions in the plasma and interstitial fluid (ISF) compartments to preserve electroneutrality and is known as Gibbs-Donnan equilibrium. In patients with hypoalbuminemia due to underlying cirrhosis, the decrease in the plasma water albumin concentration ([Alb-]pw) would be expected to r...

Muscle fibers from the giant barnacle, Balanus nubilus, were placed inside the lumen of a porous glass capillary and equilibrated for 48 h in an electrolyte solution containing 2% Tween. The glass capillary prevented the chemically "skinned" fiber from swelling with a water content beyond 80%. Isotope exchange studies using 22Na, 42K, and 36Cl indicated the existence of an intermediate rate con...

A methodology is presented for calculating of the surface potential, Donnan potential, and ion concentration profiles for semipermeable microbial membranes that is valid for an arbitrary electrolyte composition. This model for surface potential, Donnan potential, and charge density was applied to recently reported experimental data for gram-positive bacteria, including Bacillus brevis, Rhodococ...

The chemical composition of the fluid surrounding the cells of the central nervous system of Periplaneta has been shown to differ from that of the haemolymph, due to a Donnan equilibrium which maintains an excess of inorganic cations in the extracellular fluid (Treherne, 1962 a, b). In view of the demonstrated permeability of the nerve sheath to ions and molecules (Treherne, 1961 a, b) it was s...

The ionic activities and total molalities of sodium, potassium, calcium, lithium, and chloride in a solution of human serum albumin were measured at different values of pH between 4 and 9. The same quantities were measured simultaneously in a protein-free electrolyte solution in membrane equilibrium with the albumin solution. Taking the residual liquid-junction potential and bias from unselecti...

The glycosaminoglycans of isolated rabbit corneal stroma, clamped between two lucite plates at near normal hydration, were digested with testicular hyaluronidase in saline solution. After equilibration with 0.9 per cent saline solution alone the sodium and chloride content of the stroma was determined. Chloride was in equilibrium with both normal and hyaluronidase-treated stroma, allowing use o...

It has been shown, within the probable limit of error of the methods of measurement employed, that the Donnan equilibrium determines the distribution of H and Cl ions between the cell and the surrounding fluid. This equilibrium is a consequence of the impermeability of the cell membrane to the inorganic cations of the cell. The mechanism responsible for this equilibrium is suggested as that con...

Membrane potential of native isolated pepper cuticles were measured with NaCl and CaCl2 solutions for a wide range of concentrations (10BC(M)B10). From membrane potential results the fixed charge concentration, X, and the transport number of the ions in the cuticular membrane were obtained. Taking into account the X value, an estimation of the Donnan potential contribution to the membrane poten...