The membrane attack complex of complement (MAC) can induce reversible changes in cell membrane permeability resulting in significant but transient intracellular ionic changes in the absence of cell lysis. Because ion fluxes and cytosolic ionic changes are integral steps in the signaling cascade initiated when growth factors bind to their receptors, we hypothesized that the MAC-induced reversibl...

The aim of this work was to investigate the effect of phenolic acids on cell membrane permeability of lactic acid bacteria from wine. Several phenolic acids were tested for their effects on the cell membrane of Oenococcus oeni and Lactobacillus hilgardii by measuring potassium and phosphate efflux, proton influx and by assessing culture viability employing a fluorescence technique based on memb...

It has been previously demonstrated with freeze-fracture electron microscopy that vasopressin induces specific structural alterations of the luminal membrane of granular cells from toad urinary bladder in a dose-dependent fashion. These alterations consist of aggregated intramembranous particles and are observed both in the presence and absence of an osmotic gradient. We examined the effect of ...

Nuclear magnetic resonance (NMR) relaxation times were studied in acclimated and nonacclimated Kharkov winter wheat (Triticum aestivum L.) crowns and acclimated cell aggregates to determine if membrane permeability was altered by freezing. The NMR water signal decay consisted of two exponential components: a short one arising from extracellular water, and a long one arising from intracellular w...

Poly(arginine) mimics bearing long hydrophobic side chains adopt stable helical conformation and exhibit helix-related cell-penetrating properties. Elongating polypeptide backbone length and increasing side chain hydrophobicity further increase the helicities of poly(arginine) mimics. They show superior cell membrane permeability up to two orders of magnitude higher than that of HIV-TAT peptide...

We hypothesized that the deoxygenation-induced increase in cation permeability of sickle cells was related to mechanical distention of the membrane by growing HbS polymer within the cell. To test this hypothesis, we determined the effect of deoxygenation on cation fluxes in sickle cells under conditions that restricted or permitted extensive growth of polymer, producing different degrees of mem...

Objective (s): Transdermal preparations for testosterone are becoming popular because of their unique advantages such as avoidance of first-pass effect, convenience, improved bioavailability, and reduction of systemic side effects. A novel testosterone transdermal delivery system (TDDS) was developed using a palm oil base called HAMINTM (a commercial product) and tested using in vitro and in vi...

BACKGROUND The mechanical, rheological and shape properties of red blood cells are determined by their cortical cytoskeleton, evolutionarily optimized to provide the dynamic deformability required for flow through capillaries much narrower than the cell's diameter. The shear stress induced by such flow, as well as the local membrane deformations generated in certain pathological conditions, suc...