Aldosterone upregulates the Na(+)-K(+) pump in kidney and colon, classical target organs for the hormone. An effect on pump function in the heart is not firmly established. Because the myocardium contains mineralocorticoid receptors, we examined whether aldosterone has an effect on Na(+)-K(+) pump function in cardiac myocytes. Myocytes were isolated from rabbits given aldosterone via osmotic mi...

Using radio-tracers, we measured Na(+) and K(+) accumulation in roots and transport to shoots in Zea mays (cv Pioneer 3906) as a function of NaCl concentration and O(2) partial pressure in the nutrient solution. Under fully aerobic conditions, roots partially excluded Na(+) from the shoots over a wide range of NaCl concentration (0.2-200 millimolar). With root anoxia, the exclusion mechanism br...

To determine the relative salt tolerance and/or resistance in seedlings of pistachio genotypes, four pot experimentswere conducted. In experiments 1 and 2, the effects of salinity on growth indices were studid. Experiments were donein the form of split plot based on RCBD. In each experiment, mainplots consisted of different electrical conductivitiesof irrigation water (ECiws). In experiment 1, ...

The phosphorylated intermediate (EP) of the Na,K-ATPase proteoliposomes (PL) prepared from the electric eel enzyme is composed of an ADP-sensitive K+-insensitive form (E1P), an ADP- and K+-sensitive form (E*P), and a K+-sensitive ADP-insensitive form (E2P). The composition of the intermediate varied with the cholesterol content of the lipid bilayer. The PL containing less than 30 mol % choleste...

Salinity tolerance in rice, like in other glycophytes, is a function of cellular ion homeostasis. The large divergence in ion homeostasis between the salt-tolerant FL478 and salt-sensitive IR29 rice varieties can be exploited to understand mechanisms of salinity tolerance. Physiological studies indicate that FL478 shows a lower Na(+) influx, a reduced Na(+) translocation to the shoot, and maint...

Exposure of ARL 15 cells, an established line from adult rat liver, to concentrations of external K+ below 1 mM caused a rapid fall in intracellular K+ and a corresponding rise in intracellular Na+ that became maximal within 12 h. Upon continued exposure to low external K+, these initial changes were followed by a striking recovery such that, by 24 h, intracellular Na+ and K+ concentrations app...

Sodium and potassium ion contents and fluxes of isolated resting human peripheral polymorphonuclear leukocytes were measured. In cells kept at 37 degrees C, [Na]i was 25 mM and [K]i was 120 mM; both ions were completely exchangeable with extracellular isotopes. One-way Na and K fluxes, measured with 22Na and 42K, were all approximately 0.9 meq/liter cell water . min. Ouabain had no effect on Na...

Sodium and potassium ion contents and fluxes of isolated resting human peripheral polymorphonuclear leukocytes were measured . In cells kept at 37 °C, [Na]i was 25 mM and [K]i was 120 mM; both ions were completely exchangeable with extracellular isotopes . One-way Na and K fluxes, measured with 22Na and 42K, were all -0.9 meq/liter cell water -min . Ouabain had no effect on Na influx or K efflu...