Slices from the cortex corticis of the guinea pig kidney were immersed in a chilled solution without K and then reimmersed in warmer solutions. The Na and K concentrations and the membrane potential V(m) were then studied as a function of the Na and K concentrations of the reimmersion fluid. It was found that Na is extruded from the cells against a large electrochemical potential gradient. Q(10...

euryhaline teleost fishes to both freshwater and seawater environments has been studied extensively. Na+/K+-ATPase is one of the most important enzymes associated with ion regulation in the fish gill because it indirectly energizes the branchial excretion of NaCl from marine teleosts (see McCormick, 1995; Marshall and Bryson, 1998; Evans et al., 1999). The role of Na+/K+-ATPase in freshwater io...

Swensen, A. M., Golowasch, J., Christie, A. E., Coleman, M. J., Nusbaum, M. P. and Marder, E. (2000). GABA and responses to GABA in the stomatogastric ganglion of the crab Cancer borealis. J. Exp. Biol. 203, 2075–2092 Rafferty, K. L., Herring, S. W. and Artese, F. (2000). Three-dimensional loading and growth of the zygomatic arch. J. Exp. Biol. 203, 2093–2104 Logue, J. A., De Vries, A. L., Fodo...

The application of exogenous proline and glycinebetaine (betaine) confers salt tolerance on plants under salt stress. The effects of exogenous proline and betaine on apoplastic flow in rice plants under saline conditions were investigated using trisodium-8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS), an apoplastic tracer. Rice plants took up more PTS under light conditions than under dark condi...

The effects of supplemental potassium were studied on growth, ion concentration and anatomical parameters in one year old olive trees, Olea europaea L., grown in sand culture in greenhouse at different levels of NaCl for 80 days. The experiments were conducted in a completely randomized design as a factorial. Factor one was salinity (0, 40 or 80 mM NaCl) and the second factor was potassium leve...

Among genetically hypertension-prone rats, dietary sodium (chloride) was demonstrably hypertensinogenic and potassium (chloride) antihypertensinogenic. On diets containing the same NaCl but different KCl concentrations, mean blood pressure was greater in rats receiving less dietary potassium, i.e., diets with a higher Na/K molar ratio. On diets with different absolute concentrations of NaCl and...

The resting and action potentials of sartorius muscles of the toad, Bufo marinus, have been measured under varying conditions of external environment. At the same time, analyses for Na(+) and K(+) content were carried out. There was a slight elevation of 2 mv. when the measurements were made in phosphate-Ringer instead of in bicarbonate-Ringer. The R.P. was independent of the hydrogen ion conce...

This paper reports experiments designed to find the concentrations of internal and external Na and K at which inward and outward furosemide-sensitive (FS) Na and K fluxes are equal, so that there is no net FS movement of Na and K. The red cell cation content was modified by using the ionophore nystatin, varying cell Na (Nai) from 0 to 34 mM (K substitution, high-K cells) and cell K (Ki) from 0 ...

Previous studies on the relationship of local food environment with residents' diets have relied exclusively on self-reported information on diet, producing inconsistent results. Evaluation of dietary intake using biomarkers may obviate the biases inherent to the use of self-reported dietary information. This cross-sectional study examined the association between neighbourhood food store availa...