scholarly journals Intracellular Sodium Concentration and Activity Coefficient in Single Barnacle Muscle Fibers

1968 ◽  
Vol 52 (6) ◽  
pp. 984-985
Author(s):  
F. J. Brinley
Keyword(s):  
Activity Coefficient ◽  
Muscle Fibers ◽  
Sodium Concentration ◽  
Intracellular Sodium ◽  
Barnacle Muscle ◽  
Intracellular Sodium Concentration ◽  
Barnacle Muscle Fibers

scholarly journals Sodium and Potassium Fluxes in Isolated Barnacle Muscle Fibers

1968 ◽  
Vol 51 (4) ◽  
pp. 445-477 ◽  
Author(s):  
F. J. Brinley
Keyword(s):  
Time Constant ◽  
Empirical Formula ◽  
Inhibitory Concentration ◽  
Muscle Fibers ◽  
Sodium Concentration ◽  
External Loading ◽  
Barnacle Muscle ◽  
Barnacle Muscle Fibers ◽  
Sodium And Potassium ◽  
Sodium Exchange

Sodium and potassium influxes and outfluxes have been studied in single isolated muscle fibers from the giant barnacle both by microinjection and by external loading. The sodium influxes and outfluxes were 49 and 39 pmoles /cm2-sec (temperature = 15–16°C) respectively. The potassium influxes and outfluxes were 28 and 60 pmoles/cm2-sec (temperature = 13–16°C) respectively. Replacement of external sodium by lithium reduced sodium outflux by 67% but had no effect on potassium outflux. Removal of external potassum reduced the sodium outflux by 51% but had no effect on potassium outflux. External strophanthidin (10–30 µM) reduced sodium outflux by 80–90% and increased potassium outflux by 40% in normal fibers. The time constant for sodium exchange increased linearly with internal sodium concentration, as did the fraction of sodium outflux insensitive to a maximally inhibitory concentration of external strophanthidin in the range of 10 tO 80 mM internal sodium. The strophanthidin-sensitive component of sodium outflux could be related to the internal sodium concentration by the following empirical formula: See PDF for Equation

Permeability of barnacle muscle fibers to water and nonelectrolytes

1976 ◽  
Vol 30 (1) ◽  
pp. 197-212
Author(s):  
Daniel F. Wolff ◽  
Osvaldo A. Alvarez ◽  
Fernando F. Vargas
Keyword(s):  
Muscle Fibers ◽  
Barnacle Muscle ◽  
Barnacle Muscle Fibers

scholarly journals STUDY OF THE EFFECT OF HYPOTHERMIC CONSERVATION ON THE INTRACELLULAR SODIUM CONCENTRATION IN THE ENDOTHELIUM OF CORNEAL TRANSPLANTS

2018 ◽  
Vol 22 (4) ◽  
pp. 433-437
Author(s):  
G. S. Baturina ◽  
I. G. Palchikova ◽  
A. A. Konev ◽  
E. S. Smirnov ◽  
L. E. Katkova ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasma Membranes ◽  
Sodium Concentration ◽  
Intracellular Sodium ◽  
Sodium Balance ◽  
Human Cornea ◽  
Sodium Permeability ◽  
Custom Made ◽  
Intracellular Sodium Concentration ◽  
Cornea Endothelium

Endothelial keratoplasty has become the treatment of choice for corneal endothelial dysfunction. Advancements in the surgical treatment of corneal endothelial diseases depend on progress in graft conservation and its related advantages in assessing the suitability of grafts for transplantation. Transport of water and ions by cornea endothelium is important for the optic properties of cornea. In this work, we study the intracellular sodium concentration in cornea endothelial cells in samples of pig cornea that underwent hypothermic conservation for 1 and 10 days and endothelial cells of human cornea grafts after 10-day conservation. The concentration of intracellular sodium in preparations of endothelial cells was assayed using fluorescent dye SodiumGreen. The fluorescent images were analyzed with the custom-made computer program CytoDynamics. An increased level of intracellular sodium was shown in the endothelium after 10-day conservation in comparison with one-day conservation (pig samples). Sodium permeability of pig endothelial cell plasma membranes significantly decreased in these samples. Assessment of intracellular sodium in human cornea endothelium showed a higher level – as was in analogues pig samples of the corneal endothelium. The assay of the intracellular sodium balance concentration established in endothelial cells after hypothermic conservation in mediums L-15 and Optisol-GS showed a significant advantage of specialized me dium Optisol-GS. The balanced intracellular concentration after 10 days of hypothermic conservation was significantly lower in cells incubated at 4 °C in Optisol-GS (L-15, 128 ± 14,  n = 15; Optisol-GS, 108 ± 14, n = 11; mM, p < 0.001). Intracellular sodium concentration could be a useful parameter for assessing cornea endothelium cell viability.

scholarly journals Agonist-dependent Regulation of Renal Na+,K+-ATPase Activity Is Modulated by Intracellular Sodium Concentration

2002 ◽  
Vol 277 (13) ◽  
pp. 11489-11496 ◽  
Author(s):  
Riad Efendiev ◽  
Alejandro M. Bertorello ◽  
Ruben Zandomeni ◽  
Angel R. Cinelli ◽  
Carlos H. Pedemonte
Keyword(s):  
Atpase Activity ◽  
Sodium Concentration ◽  
Intracellular Sodium ◽  
Intracellular Sodium Concentration

Effects of calcium on membrane potential and sodium influx in barnacle muscle fibers

1983 ◽  
Vol 244 (3) ◽  
pp. C297-C302 ◽  
Author(s):  
S. S. Sheu ◽  
M. P. Blaustein
Keyword(s):  
Membrane Potential ◽  
Muscle Fibers ◽  
Cation Channels ◽  
Channel Blockers ◽  
Sodium Influx ◽  
Permeable Channel ◽  
Barnacle Muscle ◽  
Nonselective Cation Channels ◽  
Flux Measurements ◽  
Barnacle Muscle Fibers

The influence of internal and external Ca2+ on membrane potential and 22Na influx were tested in internally perfused giant barnacle muscle fibers. The fibers depolarized by about 2-3 mV, and Na+ influx increased when external Ca2+ was removed. These effects were inhibited and reversed by adding 2 mM La3+ externally but not by tetrodotoxin (TTX). Ca2+ channel blockers did not prevent the depolarization. Increasing internal free Ca2+ ([Ca2+]i) from 10(-7) to 10(-5) M also stimulated Na+ influx and depolarized the fibers by a few millivolts. Neither external La3+ nor TTX prevented the effects of raising [Ca2+]i; however, internal tetrabutylammonium ions depolarized the fibers and attenuated the internal Ca2+-dependent effects. These data are consistent with the idea that removal of external Ca2+ activates a La3+-sensitive channel that is permeable to Na+; raising [Ca2+]i activates a La2+-insensitive, Na+-permeable channel that may be similar to the internal Ca2+-activated nonselective cation channels observed in cardiac muscle. The results demonstrate that all Na+ (and Ca2+) fluxes that do not contribute to Na-Ca exchange must be carefully identified before the exchange stoichiometry can be determined from Na+ and Ca2+ flux measurements.

Effects of Local Anesthetics and Hemicholinium-3 on 45Ca Efflux in Barnacle Muscle Fibers

1975 ◽  
Vol 53 (2) ◽  
pp. 285-292 ◽  
Author(s):  
Stephen S. Chen
Keyword(s):  
Local Anesthetics ◽  
Inhibitory Action ◽  
Muscle Fibers ◽  
Stimulatory Action ◽  
External Application ◽  
Barnacle Muscle ◽  
Charged Form ◽  
45Ca Efflux ◽  
Barnacle Muscle Fibers ◽  
Stimulation Of

Benzocaine, which occurs in the uncharged form in the physiological range of pH, caused inhibition of 45Ca efflux in barnacle muscle fibers. By contrast, in the presence of a low external Ca2+ concentration, it produced stimulation of the efflux. Both the inhibitory and stimulatory actions of benzocaine appeared to be less potent than those of procaine. Hemicholinium-3 (HC-3), on the other hand, which exists only in the charged form, caused a large stimulation of the 45Ca efflux following microinjection, and the potency of this action was found to be at least 10 times greater than that of procaine. External application of HC-3 produced inhibition occasionally. Effects of tetracaine were similar to those produced by procaine; however, its inhibitory action was greater in more alkaline solution, which is the opposite of that observed with procaine. Lidocaine produced a less consistent effect than procaine; the inhibitory action of the former was less potent but the stimulatory action of the two anesthetics were comparable. p-Aminobenzoic acid was without effect on 45Ca efflux. These results indicate that both the charged and uncharged forms of local anesthetics are capable of causing stimulatory and inhibitory effects on 45Ca efflux in barnacle muscle fibers, and that the inhibition produced is the result of action on the Ca–Ca exchange system whereas the stimulation is the result of release of Ca from internal storage sites.

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