Photosynthetic characteristics, leaf ionic content, and net fluxes of Na(+), K(+), and Cl(-) were studied in barley (Hordeum vulgare L) plants grown hydroponically at various Na/Ca ratios. Five weeks of moderate (50 mM) or high (100 mM) NaCl stress caused a significant decline in chlorophyll content, chlorophyll fluorescence characteristics, and stomatal conductance (g(s)) in plant leaves grown...

The influence of exogenous application of glycine betaine (GlyBet) was examined on photosynthetic pigments and ions concentration of safflower under salinity stress conditions. The experiment was performed in a randomized complete block design arranged as a factorial with three replications. Salinity treatments (0, 50, 100, and 150 mM) were applied using sodium chloride (NaCl). GlyBet (0, 10, 3...

In this study, biodegradation of corn starch/glycerol/Na-MMT nanocomposites by soil burial tests were carried out for up to 6 months. Films were prepared by casting method according to central composite design and response surface methodology was applied for analysis of the results. The effects of formulation on the water solubility, contact angle and tensile strength of starch films were inves...

In ecological setting, sodium (Na(+)) can be beneficial or toxic, depending on plant species and the Na(+) level in the soil. While its effects are more frequently studied at high saline levels, Na(+) has also been shown to be of potential benefit to some species at lower levels of supply, especially in C4 species. Here, clonal plants of the major tropical C3 crop Theobroma cacao (cacao) were g...

Our purpose was to study the interaction between Na(+) content and fluid volume on rehydration (RH) and restoration of fluid spaces and cardiovascular (CV) function. Ten men completed four trials in which they exercised in a 35 degrees C environment until dehydrated by 2. 9% body mass, were rehydrated for 180 min, and exercised for an additional 20 min. Four RH regimens were tested: low volume ...

The method describes a simultaneous determination of inorganic phosphate (Pi) and protein content from a reaction mixture used for assay of adult rat cerebrocortical synaptosomal membrane Na+-K+-ATPase specific activity. The present method is more convenient, accurate and quicker compared to the existing methods for the determination of Na+-K+-ATPase activity. It also eliminates the possible er...

BACKGROUND Recent data suggest that sodium (Na+ ) is stored in the muscle and skin without commensurate water retention in maintenance hemodialysis (MHD) patients. In this study, we hypothesized that excessive Na+ accumulation would be associated with abnormalities in peripheral insulin action. METHODS Eleven MHD patients and eight controls underwent hyperinsulinemic-euglycemic-euaminoacidemi...

Cardiac hypertrophy was induced in rats by daily injection of isoproterenol (5 mg/kg ip) for 7 days. Membrane voltage and currents were recorded using the whole cell patch-clamp technique in left ventricular myocytes from control and hypertrophied hearts. Ryanodine-sensitive delayed afterdepolarizations (DADs) and transient inward current (I(ti)) appeared in hypertrophied cells more often and w...

Although the phenotypes of many membrane-excitation mutants of Paramecium are best expressed in Na+-containing solutions, little is known about the role of Na+ in membrane excitation in Paramecium. By measuring 22Na fluxes, we have shown that: (a) The total cellular Na+ content is equivalent to a cytoplasmic concentration of 3--4 mM, if the Na+ concentration is uniform throughout the cell. (b) ...