Changes in activity or expression of transporters may account for alterations in cell behavior in diabetes. We sought to ascertain if mesangial cells (MC) grown in different glucose concentrations exhibit changes in activity and expression of acid-extruding transporters, the Na(+)/H(+) and Na(+)-dependent Cl(-)/HCO(-)(3) exchanger. pH(i) was determined by the use of the fluorescent pH-sensitive...

In this work, a series of hydrogel nanocomposites were prepared by grafting acrylic acid and acrylamide on gelatin in the presence of Na-montmorillonite (Na-MMT) nanoparticles. The characterizations of hydrogel nanocomposites were examined by swelling experiments, Fourier transform infrared (FT-IR) spectroscopy, X-Ray diffraction (XRD) patterns and thermogravimetric analysis (TGA). Scanning ele...

We assessed the physico-chemical status of twelve surface water samples from the Birjand flood plain (east of Iran) during fall 2010. The sampling points were selected on the basis of their importance. The physico-chemical parameters such as pH, temperature (T), electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), calcium (Ca2+), magnesium (Mg2+ ), sodium (Na+), pota...

This study provides the first information about pHi regulatory mechanisms in human retinal pigment epithelium (RPE). The experiments were carried out on fresh explant tissues from adult donor and fetal eyes, and pHi was measured using fluorescence microscopy techniques and the pH-sensitive dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. In adult donor RPE, the resting pHi is 7.30 +/- 0.14 ...

Everted membrane vesicles of Streptococcus faecalis accumulated “Na+ to a nominal concentration gradient of about 100 when incubated with ATP and M&+. The characteristics of “Na+ accumulation varied in a complex manner as a function of the pH and of the ionic environment. To illustrate, when the vesicles were prepared in potassium ma1eate:Hepes:sucrose buffer (0.45 N K+) and incubated in the sa...

Intracellular pH may be an important variable regulating neurotransmitter release. A number of pathological conditions, such as anoxia and ischemia, are known to influence intracellular pH, causing acidification of brain cells and excitotoxicity. We examined the effect of acidification on quantal glutamate release. Although acidification caused only modest changes in release, recovery from acid...

A new kinetic model of the Na(+)/H(+) exchanger (NHE) was developed by fitting a variety of major experimental findings, such as ion-dependencies, forward/reverse mode, and the turnover rate. The role of NHE in ion homeostasis was examined by implementing the NHE model in a minimum cell model including intracellular pH buffer, Na(+)/K(+) pump, background H(+), and Na(+) fluxes. This minimum cel...

BACKGROUND The epithelium lining the epididymis provides an optimal acidic fluid microenvironment in the epididymal tract that enable spermatozoa to complete the maturation process. The present study aims to investigate the functional role of Na(+)/HCO(3)(-) cotransporter in the pH regulation in rat epididymis. METHOD/PRINCIPAL FINDINGS Immunofluorescence staining of pan cytokeratin in the pr...

Type II Na/P(i) cotransporters play key roles in epithelial P(i) transport and thereby contribute to overall P(i) homeostasis. Renal proximal tubular brush border membrane expresses the IIa isoform, whereas the IIb isoform is preferentially expressed in small intestinal brush border membrane of mammals. IIa and IIb proteins are predicted to contain eight transmembrane domains with the N- and C-...