Cells of Porphyra perforata, a red marine alga, accumulate K in the absence of concomitant Na or Li extrusion while immersed in Li- or Mg-sea waters lacking Na. This suggests that the coupling observed between K and Na transport is facultative. No evidence is obtained for net extrusion of Li. Na efflux, with the concentration gradient, is facilitated by K and is proportional to the cellular Na ...

Illumination causes the extrusion of protons from Halobacterium halobium cell envelope vesicles, as a result of the action of light on bacteriorhodopsin. The protonmotive force developed is coupled to the active transport of Na+ out of the vesicles. The light-dependent ion fluxes in these vesicles were studied by following changes in the external pH, in the fluorescence of the dye, 3,3'-dipenty...

The activity of the sodium-potassium (Na+-K+) pump in arterial tissue from rats with chronic DOCA-salt or one-kidney Grollman renal hypertension was assayed in vitro as the rate of ouabain-sensitive 86Rb+ uptake. Estimates of total cell Na+ and tissue K+ were made by a lithium-substitution method on the same segment of arterial tissue. In both freshly excised tail arteries and aortas, and in ao...

PURPOSE In a previous study, an increase in Na,K-ATPase alpha 2 expression was detected in the epithelium of porcine lenses exposed to amphotericin B, an ionophore that also increases lens sodium and stimulates active sodium transport. The purpose of the present study was to determine whether an increase of Na,K-ATPase alpha 2 synthesis is a response to an episode of rapid Na-K transport or whe...

Genetic and physiological data establish that Arabidopsis AtHKT1 facilitates Na(+) homeostasis in planta and by this function modulates K(+) nutrient status. Mutations that disrupt AtHKT1 function suppress NaCl sensitivity of sos1-1 and sos2-2, as well as of sos3-1 seedlings grown in vitro and plants grown in controlled environmental conditions. hkt1 suppression of sos3-1 NaCl sensitivity is li...

The matching of energy supply and demand under hypoxic conditions is critical for sustaining myocardial function. Numerous reports indicate that basal energy requirements and ion handling may differ between the ventricles. We hypothesized that ventricular response to hypoxia shows interventricular differences caused by the heterogeneity in glucose metabolism and expression and activity of ion t...

abstract- olive (olea europaea l.) is one of the most valuable and widespread fruit trees in iran. salt stress-induced changes in membrane stability, photosynthesis and antioxidant enzyme activity were examined on four olive cultivars (dakal, shiraz, zard and amigdalifolia) by emphasizing the correlation between measured parameters and ion (k+, na+) accumulation. plants were subjected to four s...

Sciortino, Christopher M., and Michael F. Romero. Cation and voltage dependence of rat kidney electrogenic Na-HCO3 2 cotransporter, rkNBC, expressed in oocytes. Am. J. Physiol. 277 (Renal Physiol. 46): F611–F623, 1999.— Recently, we reported the cloning and expression of the rat renal electrogenic Na-HCO3 2 cotransporter (rkNBC) in Xenopus oocytes [M. F. Romero, P. Fong, U. V. Berger, M. A. Hed...