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1. Radioisotopes and intracellular microelectrodes were used to characterize the permeability of Xenopus oocytes to chloride and other halides. 2. Uptake of 36Cl had a half-time for equilibration of approximately 3 h, with an initial rate of Cl- entry corresponding to a permeability coefficient of 3.9 x 10(-7) cm/s, and an equilibrium uptake of 36Cl of 33 mM. 3. Replacement of bathing Na+ by K+ depolarized the oocytes from -46 to -7 mV and stimulated influx approximately 3-fold. 4. Influx was linearly dependent on bathing [Cl-] and was temperature dependent with an activation energy of 46 kJ/mol. Influx of 125I of 36Cl was not affected by the presence of equal concentrations of other halides or thiocyanate. These results are consistent with a channel-mediated entry mechanism. 5. Diphenylamine-2-carboxylate (DPAC) and 9-anthracene carboxylate (9-AC), blockers of Cl- channels in other cells, inhibited Cl- entry with dissociation constants (Kds) of approximately 5 x 10(-4) and approximately 10(-3) M, respectively. Inhibitors of Cl(-)-HCO3- exchange or Na(+)-K(+)-2Cl- co-transport did not affect Cl- influx. 6. Attempts to lower or raise intracellular Ca2+ with BAPTA or A23187, respectively, were also without effect on Cl- influx. 7. The halide selectivity sequence determined with isotopes was I- (3.2) greater than Br- (1.3) greater than Cl- (1.0). However, DPAC inhibited almost all of the 36Cl influx but only a small fraction of 125I influx. 8. Replacement of bathing Cl- by I- or Br-resulted in hyperpolarizations, from which the same selectivity sequence was determined. 9. Replacement of bathing Cl- by gluconate caused a marked depolarization, which was inhibited by DPAC and, less potently, by 9-AC.
Armstrong,
Ionic pores, gates, and gating currents.
1974, Pubmed
Armstrong,
Ionic pores, gates, and gating currents.
1974,
Pubmed
Bryant,
Chloride conductance in normal and myotonic muscle fibres and the action of monocarboxylic aromatic acids.
1971,
Pubmed
Burnham,
Expression of the Na(+)-K(+)-2Cl- cotransporter in Xenopus oocytes.
1990,
Pubmed
,
Xenbase
Cabantchik,
Membrane proteins related to anion permeability of human red blood cells. I. Localization of disulfonic stilbene binding sites in proteins involved in permeation.
1974,
Pubmed
Dascal,
Xenopus oocyte resting potential, muscarinic responses and the role of calcium and guanosine 3',5'-cyclic monophosphate.
1984,
Pubmed
,
Xenbase
Dascal,
The use of Xenopus oocytes for the study of ion channels.
1987,
Pubmed
,
Xenbase
Dumont,
Oogenesis in Xenopus laevis (Daudin). I. Stages of oocyte development in laboratory maintained animals.
1972,
Pubmed
,
Xenbase
Frizzell,
Altered regulation of airway epithelial cell chloride channels in cystic fibrosis.
1986,
Pubmed
Gray,
Two types of chloride channel on duct cells cultured from human fetal pancreas.
1989,
Pubmed
Hinton,
Expression of amiloride-blockable sodium channels in Xenopus oocytes.
1989,
Pubmed
,
Xenbase
Li,
Cyclic AMP-dependent protein kinase opens chloride channels in normal but not cystic fibrosis airway epithelium.
1988,
Pubmed
Miledi,
A calcium-dependent transient outward current in Xenopus laevis oocytes.
1982,
Pubmed
,
Xenbase
O'Grady,
Characteristics and functions of Na-K-Cl cotransport in epithelial tissues.
1987,
Pubmed
Palade,
On the inhibition of muscle membrane chloride conductance by aromatic carboxylic acids.
1977,
Pubmed
Parsegian,
Energy of an ion crossing a low dielectric membrane: solutions to four relevant electrostatic problems.
1969,
Pubmed
Schoppa,
Voltage-gated chloride currents in cultured canine tracheal epithelial cells.
1989,
Pubmed
Schoumacher,
Phosphorylation fails to activate chloride channels from cystic fibrosis airway cells.
,
Pubmed
Sigel,
Use of Xenopus oocytes for the functional expression of plasma membrane proteins.
1990,
Pubmed
,
Xenbase
Stinnakre,
Cyclic adenosine monophosphate, calcium, acetylcholine and the current induced by adenosine in the Xenopus oocyte.
1986,
Pubmed
,
Xenbase
Takahashi,
Rat brain serotonin receptors in Xenopus oocytes are coupled by intracellular calcium to endogenous channels.
1987,
Pubmed
,
Xenbase
Tupper,
The ionic permeability of the amphibian oocyte in the presence or absence of external calcium.
1973,
Pubmed
Wangemann,
Cl(-)-channel blockers in the thick ascending limb of the loop of Henle. Structure activity relationship.
1986,
Pubmed
Welsh,
Anthracene-9-carboxylic acid inhibits an apical membrane chloride conductance in canine tracheal epithelium.
1984,
Pubmed
Welsh,
Cystic fibrosis.
1987,
Pubmed
de Laat,
Intracellular ionic distribution, cell membrane permeability and membrane potential of the Xenopus egg during first cleavage.
1974,
Pubmed
,
Xenbase
