J F Garcia-Diaz

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The sodium-selective ligand 1,1,1-tris[1(1)-(2(1)-oxa-4(1)-oxo-5(1)-aza-5(1)-methyl)dodecanyl]propane dissolved in 3-nitro-o-xylene containing a small amount of the lipophilic anion tetrachlorophenyl borate was used as a liquid ion-exchanger in sodium-selective microelectrodes. The microelectrodes gave rapid, stable responses that were linear functions of(More)
Intracellular Na+, K+, and Cl- activities (aiNa, aiK, aiCl) and transapical membrane potentials (V0) were measured with liquid ion-exchanger and open-tip microelectrodes in isolated short-circuited frog skins (R. pipiens) incubated at 23 degrees C in normal amphibian Ringer's solution. Under control conditions aiNa = 14 +/- 3 mM, aiK = 132 +/- 10 mM and(More)
In voltage-clamped epithelia the cell membrane potential transient during a + 10-mV transepithelial pulse conforms to the expected behavior for a series combination of two linear resistance-capacitance (RC) circuits. The evolution of the cell potential is characterized by a single time constant with values of 30-130 ms in frog skin and Necturus gallbladder.(More)
In studies of apical membrane current-voltage relationships, in order to avoid laborious intracellular microelectrode techniques, tight epithelia are commonly exposed to high serosal K concentrations. This approach depends on the assumptions that high serosal K reduces the basolateral membrane resistance and potential to insignificantly low levels, so that(More)
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