Effect of temperature on membrane potential and ionic fluxes in intact and dialysed barnacle muscle fibres

DiPolo, Reinaldo; Latorre, Ramon

doi:10.1113/jphysiol.1972.sp009939

Cited by 34 publications

(18 citation statements)

References 21 publications

(30 reference statements)

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“…They show that solutions of K acetate, isethionate, aspartate and glutamate allow the fibres to give values for the resting potential which are close to those reported by Keynes et al (1973), by DiPolo (1972) and DiPolo & Latorre (1972 In the case of KCN, although one could anticipate its destructive effect on the cell at the high concentration used (200 mM), it should be stated that the instantaneous value of the resting potential was about -40 mV and in about 10 min the fibre became opaque and the resting potential was completely abolished.…”

Section: Resultssupporting

confidence: 71%

“…Extension of these methods to other cells or fibres was prevented by their small size (Davies, 1961). However, with the availability of giant barnacle muscle fibres (Hoyle & Smyth, 1963a, b) the techniques of intracellular injection (Hagiwara & Naka, 1964;Hagiwara, Chichibu & Naka, 1964;Hagiwara, Naka & Chichibu, 1964;Brinley, 1968), dialysis DiPolo & Latorre, 1972;DiPolo, 1972) and perfusion (Keynes, Rojas, Taylor & Vergara, 1973) have been applied to study their behaviour in various environments. Keynes et al (1973) have described a method for internally perfusing the single barnacle muscle fibre from Megabalanus psittacus (Darwin).…”

Section: Introductionmentioning

confidence: 99%

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Effects of anions and cations on the resting membrane potential of internally perfused barnacle muscle fibres

Lakshminarayanaiah¹,

Rojas²

1973

The Journal of Physiology

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SUMMARY1. Single barnacle muscle fibres from Megabalanus psittacus (Darwin) were internally perfused with a number of K salt solutions (200 mm) which were made isotonic to the barnacle saline with sucrose.2. 200 mM-K acetate solution, in general, was found to be more effective than other solutions of K salts in generating and maintaining stable resting membrane potential of -56-0 + 0 7 mV (all potentials are referred to the external solutions as ground). The various K salts, on the basis of the magnitude of the resting potential they generated in the muscle fibres, followed the 7. Complete elimination of K in the external solution and reduction of its ionic strength using sucrose depolarized the muscle fibres by about 27 mV when Na was changed from 475 to 1 mm. Under these conditions, external solutions completely in acetate form gave resting potentials which were more positive than -those observed in completely chloride solutions by 6-8 mV.8. Replacement of Na by Li, Tris, choline, tetramethyl or tetraethyl ammonium ion in the external solution made the values of the resting potential more positive (depolarization). Similarly increasing the concentration of K (or Cs or Rb in place of K) by correspondingly decreasing the concentration of Na in the outside solution depolarized the fibres and the resting potential became zero at a concentration of 280 mm (or 308 or 1500 mm for Rb or Cs, respectively) on extrapolation.

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Section: Resultssupporting

confidence: 71%

Section: Introductionmentioning

confidence: 99%

Effects of anions and cations on the resting membrane potential of internally perfused barnacle muscle fibres

Lakshminarayanaiah¹,

Rojas²

1973

The Journal of Physiology

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“…Since the fibers were dialyzed with tracer-free solution for 40-70 min before isotope was added, most of the membrane hyper-polarization occurred before isotopic flux measurements were begun. The average steady resting potential was -50 mV (cf Tables 1 and 3) which is quite close to the -53 mV value reported by DiPolo and LaTorre (1972) and -58 mV reported by DiPolo (1972). The difference between their values and ours may be due to the fact that our experiments were conducted at 15 ~ rather than 22 ~ and the lower temperature would be expected to depolarize the membrane (DiPolo & LaTorre, 1972).…”

Section: Membrane Potentialsupporting

confidence: 67%

“…The internal dialysis technique (Brinley & Mullins, 1967) would appear to be well-suited to this problem. The dialysis technique has been adapted for the study of univalent ion fluxes in barnacle muscle (DiPolo, 1972;DiPolo & LaTorre, 1972), and has recently been used successfully for Ca influx measurements in this preparation (DiPolo, 1973).…”

mentioning

confidence: 99%

Calcium fluxes in internally dialyzed giant barnacle muscle fibers

Russell

Blaustein

1975

J. Membrain Biol.

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Calcium-45 fluxes have been examined in isolated giant barnacle muscle fibers subjected to internal solute control by means of "internal dialysis". The 45Ca efflux was dependent upon the concentrations of both total and ionized internal Ca (Ca2+ buffered with EGTA). With a total Ca concentration of 2.0 mM and a 1:2 Ca/EGTA ratio (nominal [Ca2+]i =0.13 muM), the Ca efflux averaged 1.2 pmoles/cm2 sec. Under identical conditions, the mean Ca influx was only 0.36 pmoles/cm2 sec. The Ca efflux may not be attributed to leak of the CaEGTA complex, since a 2.5-fold increase in the EGTA concentration (nominal [Ca2+]i=0.032 muM) reduced the 45Ca efflux by one-third. Furthermore, when EDTA was used to buffer the internal Ca concentration (in the absence of internal Mg), the steady efflux of 14C-EDTA was only about 10% of the 45Ca efflux (in parallel experiments). The timecourse of the 45Ca fluxes also appeared anomalous in the 45Ca influx reached a steady level much more rapidly than 45Ca efflux in fibers of comparable diameters. If the muscle fibers are treated as right circular cylinders, these data imply that the apparent diffusion coefficient for inwardly-moving Ca is much larger than for outwardly-moving Ca. In contrast to Ca efflux, the outward diffusion of 22Na, 14C-EDTA and 3H2O appears to be limited primarily by the permeability of the dialysis tube wall. Some, but not all, of the anomalous behavior of the Ca fluxes can be reconciled if the deep, branched infoldings of the barnacle muscle surface membrane are taken into account.

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“…The resting potential measured perfusingg with 180 mm-K aspartate) at 20 + 2°C was -56 + 2 mV and the resting potential measured at 9 + 1°C was -46 + 3 mV (see also DiPolo & Latorre, 1972).…”

Section: Resting Potentialmentioning

confidence: 99%

Calcium and potassium systems of a giant barnacle muscle fibre under membrane potential control

Keynes¹,

Rojas²,

Taylor³

et al. 1973

The Journal of Physiology

165

143

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R. D. KEYNES AND OTHERS6. Both the size of the outward currents and the rate at which they reached their maximum value increased with temperature. The activation energy for the rate constant was about 63 kJ/mole.7. Fibres bathed in Na-and Mg-free, 60 mM-CaCl2 saline were excitable. After replacement of the internal K+ with Cs+ or adding 60 mM-TEA to the internal solution only sustained inward currents were recorded with depolarization.8. Sustained inward currents could be reduced by external application of 5 mm-LaCl3. Tetrodotoxin was not effective even at a concentration of 1000 nM.9. The rate at which these inward currents reached a maximum value increased with increase in temperature of the bathing solution with an activation energy of the order of 42 kJ/mole.10. The reversal potential of the inward currents changed with the level of internal Ca-ions. For a fibre perfused without ethyleneglycol-bis

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Effect of temperature on membrane potential and ionic fluxes in intact and dialysed barnacle muscle fibres

Cited by 34 publications

References 21 publications

Effects of anions and cations on the resting membrane potential of internally perfused barnacle muscle fibres

Effects of anions and cations on the resting membrane potential of internally perfused barnacle muscle fibres

Calcium fluxes in internally dialyzed giant barnacle muscle fibers

Calcium and potassium systems of a giant barnacle muscle fibre under membrane potential control

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