BACKGROUND Adenosine A(1) receptor blockade has been suggested as a treatment in conditions with sodium and fluid retention because it increases urinary Na(+) excretion and increases proximal tubular fluid output. In the present study, we examine the time course for the renal responses to adenosine A(1) receptor blockade in order to investigate whether the effects may be prolonged and not just ...

A 2-fold interwoven metal-organic framework has been chemically reduced and doped with Li(+), Na(+), and K(+). At low pressures and temperatures, the reduced and doped materials exhibit enhanced H2 uptakeup to 65% higher than for the neutral framework. Notably, at similar doping levels, H2 binding is strongest with Li(+) and decreases as Li(+) > Na(+) > K(+). However, the uptake increases in th...

Red blood cell Li-Na countertransport and Na-K cotransport activities, home blood pressure, invasive systemic hemodynamics, and limb venous compliance were measured in 65 white men (23 normotensive, 22 borderline hypertensive, and 20 mild essential hypertensive subjects). Li-Na countertransport activity was positively and significantly correlated with subject-determined home systolic blood pres...

The X-ray structure of KcsA, a eubacterial potassium channel, displays a selectivity filter composed of four parallel peptide strands. The backbone carbonyl oxygen atoms of these strands solvate multiple K(+) ions. KcsA structures show different distributions of ions within the selectivity filter in solutions containing different cations. To assess the interactions of cations with the selectivi...

The bacterial Na+ (Li+)/H+ antiporter NhaA has been expressed in the yeast Saccharomyces cerevisiae. NhaA was present in both the plasma membrane and internal membranes, and it conferred lithium but not sodium tolerance. In cells containing the yeast Ena1-4 (Na+, Li+) extrusion ATPase, the extra lithium tolerance conferred by NhaA was dependent on a functional vacuolar H+ ATPase and correlated ...

Compound resting membrane potential was recorded by the grease gap technique during normoxic conditions (37 degrees C) in rat optic nerve, a representative CNS myelinated tract. Mean potential was -47 +/- 3 (SD) mV and remained stable for 2-3 h. Input impedance of a single optic nerve axon was calculated to be approximately 5 Gomega. Contribution of the Na+ pump to resting axonal potential is e...

The volume changes of lithium and sodium under pressure are discussed with respect to the packing density of the atoms and their valence. In densely packed Li I (bcc), Li II (fcc), and Li III (α-Hg type), valence increases from 1 at ≈ 5 GPa to ≈ 2.5 at 40 GPa. The maximum valence 3 is attained in Li IV (body-centered cubic, 16 atoms per cell, packing density q = 0.965) at 47 GPa. In densely pac...

Li3InBr6 and NaInBr4 have been synthesized and characterized by means of DTA, 8 'Br NQR, Li, Li, Na, and l l In NMR, and AC conductivity. These measurements revealed the presence of phase transitions and cationic diffusion in both compounds. From the spin-lattice relaxation times of 1 Br NQR and the peak widths of Li and Na NMR spectra, it is deduced that the conduction is due to cationic diffu...

The epithelial Na(+) channel (ENaC) is present in the apical membrane of "tight" epithelia in the distal nephron, distal colon, and airways. Its activity controls the rate of transepithelial sodium transport. Among other regulatory factors, ENaC activity is controlled by the concentration of extracellular Na(+), a phenomenon named self-inhibition. The molecular mechanism by which extracellular ...

Frog sartorius muscles were made Na-rich by immersion in K-free sulfate Ringer's solution in the cold. The muscles were then loaded with Na(24) and the extracellular space cleared of radioactivity. When such Na-rich muscles were transferred to lithium sulfate Ringer's solution at 20 degrees C, Na efflux was observed to increase with time, to reach a maximum about 15 minutes after the transfer o...