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

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.

Effects of organic solutes on the Raman spectra of barnacle muscle fibers

1987 ◽  
Vol 65 (7) ◽  
pp. 1416-1420 ◽  
Author(s):  
Jean-Pierre Caillé ◽  
Marie Pigeon-Gosselin ◽  
Michel Pézolet
Keyword(s):  
Raman Spectra ◽  
Sea Water ◽  
Muscle Fibers ◽  
Extraction Procedure ◽  
Organic Solutes ◽  
Experimental Conditions ◽  
Scattering Intensity ◽  
Barnacle Muscle ◽  
Α Helix ◽  
Barnacle Muscle Fibers

The Raman spectra observed from barnacle muscle fibers are quite complex because the cytoplasm of these cells contains several proteins and solutes. An extraction procedure was used to separate organic solutes from the contractile proteins. Glycine, trimethylamine oxide, taurine, and alanine were found to contribute to the Raman spectra of barnacle muscle fibers, while spectra of lobster fibers reveal the presence of betaine in addition. We have observed that the increase in osmolarity of the intracellular fluid caused by the augmentation of the salinity of sea water (density, 1.023–1.030) in which the barnacles were kept, induces a reduction of intensity of the amide I band. To distinguish among the different parameters which are modified by the sea water salinity, observations were made on glycerinated barnacle muscle fibers. The reduction of intensity of the amide I band in the Raman spectra of glycerinated muscle fibers was also observed with the addition of taurine (0.08 M) in the external relaxing solution. Therefore, under these experimental conditions, the Raman scattering intensity in the amide I region assigned to the α-helix conformation (1645–1650 cm−1) is increased when the concentration of organic electrolytes is reduced. However, as no significant decrease of the scattering intensity in the 1660–1670 cm−1 region where the amide I bands of either β-sheet or disordered conformations normally appear was observed, the increase of intensity of the amide I band centered at 1645 cm−1 is assigned to a change of orientation of α-helical segments of the myosin molecules. Our results suggest that organic solutes influence the position of the S-2 segments relative to the thick filaments.

Further observations of aldosterone response in barnacle muscle fibers

1983 ◽  
Vol 245 (3) ◽  
pp. E230-E238
Author(s):  
R. B. Tallitsch
Keyword(s):  
Dose Response ◽  
Muscle Fibers ◽  
External Application ◽  
Barnacle Muscle ◽  
Mitochondrial Inhibitors ◽  
Glucocorticoid Response ◽  
Saturation Kinetics ◽  
Barnacle Muscle Fibers

Work with single muscle fibers from the barnacle Balanus nubilus has revealed that these fibers can be rendered sensitive to external application of aldosterone by preexposing the barnacle in vivo to the steroid for 16 h. Experiments investigating the dose-response relationship, glucocorticoid sensitivity of the preparation, and the role of the mitochondria in the aldosterone response in this preparation are presented. It is demonstrated that saturation kinetics may be seen in the dose-response curve if care is taken to isolate only fibers from animals that are in midmolt cycle. Data is presented that demonstrated a specific mineralocorticoid response to aldosterone in this preparation rather than a combined mineralocorticoid-glucocorticoid response, as has been demonstrated in other preparations. Experiments investigating the role of the mitochondrial inhibitors and substrates suggest that aldosterone modulates Na efflux in barnacle muscle fibers by altering mitochondrial function, presumably at the level of succinic hydrogenase.

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

The influence of caffeine on the sodium efflux in barnacle muscle fibers

1972 ◽  
Vol 28 (9) ◽  
pp. 1031-1033 ◽  
Author(s):  
E. Y. Tong ◽  
E. E. Bittar ◽  
S. S. Chen ◽  
B. G. Danielson
Keyword(s):  
Muscle Fibers ◽  
Sodium Efflux ◽  
Barnacle Muscle ◽  
Barnacle Muscle Fibers

Diphenylhydantoin as a blocking agent of the proton-sensitive component of Na efflux in barnacle muscle fibers

Life Sciences ◽  
1971 ◽  
Vol 10 (13) ◽  
pp. 721-726 ◽  
Author(s):  
Bo G. Danielson ◽  
E.Edward Bittar ◽  
Stephen S. Chen ◽  
Edmund Y. Tong
Keyword(s):  
Muscle Fibers ◽  
Blocking Agent ◽  
Barnacle Muscle ◽  
Na Efflux ◽  
Barnacle Muscle Fibers
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