Co-mixed cellulose acetate butyrate and permutit in a definite composition was prepared and coded as MRS-2.The membrane potential was measured with uni-uni valent electrolyte, NaCl solutions using saturated calomel electrodes (SCEs).The effective fixed charge density of the membrane was determined by TMS method and it showed dependence on the porosity, charge on the membrane matrix, charge and ...

Volume changes of the transverse tubular system (T system) of frog sartorius in different solutions can be explained by a model which assumes fixed negative charges in the T system lumen, an open T system mouth, and a Donnan equilibrium between the T system and external solution. The T system volume is regulated by the osmotic pressure difference between the lumen and external solution, as well...

Nanofiltration of a solution containing four monovalent ions has been carried out to assess the Donnan steric and dielectrical exclusion pore model (DSDE-PM). The sequences of the ions rejections were Li > Cl > IO3 > K and IO3 > K > Li > Cl when membrane was positive or negative charged, respectively. Several types of ionic radii were implemented either in the interfaces equilibrium or in trans...

Red blood cells from mature dogs contain less Na and more K than would be the case if they were in Donnan equilibrium with plasma. They have no ouabain-sensitive Na pump, and their membranes are deficient in Na, K-ATPase. Experiments are reported in which dog red cells were first loaded with supranormal quantities of Na and water and then reinjected into the dog. Over the course of 26-40 h the ...

The kinetics of initiation of germination and inactivation by hydrostatic pressure of phosphate-buffered Bacillus pumilus spores is shown to be a consecutive first-order process at 25 C. The effect of increasing pressure at constant temperature was studied, and rate constants were derived by using the criteria of heat resistance, refractility, and stainability. The calculated volume change of a...

The availability of therapeutic molecules to targets within cartilage depends on transport through the avascular matrix. We studied equilibrium partitioning and non-equilibrium transport into cartilage of Pf-pep, a 760 Da positively charged peptide inhibitor of the proprotein convertase PACE4. Competitive binding measurements revealed negligible binding of Pf-pep to sites within cartilage. Upta...

In several previous experiments to determine the composition of interstitial fluid, the results varied depending on the collecting technique, and the electrolyte concentrations differed from those of a hypothetical ultrafiltrate of plasma. In our approach, since a change of position from standing to supine is accompanied by hemodilution with interstitial fluid, we used the changes in hematocrit...