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Equilibrium properties of a voltage-dependent junctional conductance.
Spray DC
,
Harris AL
,
Bennett MV
.
Abstract
The conductance of junctions between amphibian blastomeres is strongly voltage dependent. Isolated pairs of blastomeres from embryos of Ambystoma mexicanum, Xenopus laevis, and Rana pipiens were voltage clamped, and junctional current was measured during transjunctional voltage steps. The steady-state junctional conductance decreases as a steep function of transjunctional voltage of either polarity. A voltage-insensitive conductance less than 5% of the maximum remains at large transjunctional voltages. Equal transjunctional voltages of opposite polarities produce equal conductance changes. The conductance is half maximal at a transjunctional voltage of approximately 15 mV. The junctional conductance is insensitive to the potential between the inside and outside of the cells. The changes in steady-state junctional conductance may be accurately modeled for voltages of each polarity as arising from a reversible two-state system in which voltage linearly affects the energy difference between states. The voltage sensitivity can be accounted for by the movement of about six electron charges through the transjunctional voltage. The changes in junctional conductance are not consistent with a current-controlled or ionic accumulation mechanism. We propose that the intramembrane particles that comprise gap junctions in early amphibian embryos are voltage-sensitive channels.
Bennett,
Gap junctions, electrotonic coupling, and intercellular communication.
1978, Pubmed,
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Bennett,
Gap junctions, electrotonic coupling, and intercellular communication.
1978,
Pubmed
,
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Bennett,
Permeability of gap junctions between embryonic cells of Fundulus: a reevaluation.
1978,
Pubmed
Ehrenstein,
Electrically gated ionic channels in lipid bilayers.
1977,
Pubmed
Ehrenstein,
Kinetics of the opening and closing of individual excitability-inducing material channels in a lipid bilayer.
1974,
Pubmed
Ehrenstein,
The nature of the negative resistance in bimolecular lipid membranes containing excitability-inducing material.
1970,
Pubmed
FLICKINGER,
A study of the metabolism of amphibian neural crest cells during their migration and pigmentation in vitro.
1949,
Pubmed
Hanna,
The fine structure of a rectifying electrotonic synapse.
1978,
Pubmed
Hanna,
Gap junctions in early amphibian embryos.
1980,
Pubmed
Harris,
Kinetic properties of a voltage-dependent junctional conductance.
1981,
Pubmed
Kater,
Physiological and morphological evidence for coupling in mouse salivary gland acinar cells.
1978,
Pubmed
Meech,
The effect of calcium injection on the intracellular sodium and pH of snail neurones.
1977,
Pubmed
Rink,
Free calcium in Xenopus embryos measured with ion-selective microelectrodes.
1980,
Pubmed
,
Xenbase
Rose,
Permeability of cell junction depends on local cytoplasmic calcium activity.
1975,
Pubmed
Schein,
Reconstitution in planar lipid bilayers of a voltage-dependent anion-selective channel obtained from paramecium mitochondria.
1976,
Pubmed
Spray,
Voltage dependence of junctional conductance in early amphibian embryos.
1979,
Pubmed
,
Xenbase
Stewart,
Functional connections between cells as revealed by dye-coupling with a highly fluorescent naphthalimide tracer.
1978,
Pubmed
Turin,
Carbon dioxide reversibly abolishes ionic communication between cells of early amphibian embryo.
1977,
Pubmed
,
Xenbase
