Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
External Ni2 + and ENaC in A6 cells: Na+ current stimulation by competition at a binding site for amiloride and Na+.
Cucu D
,
Simaels J
,
Van Driessche W
,
Zeiske W
.
???displayArticle.abstract???
In cultured A6 monolayers from distal Xenopus kidney, external Ni2+ stimulated active Na+ uptake via the epithelial Na+ channel, ENaC. Transepithelial capacitance measurements ruled out exocytosis of ENaC-containing vesicles underlying the Ni2+ effect. Na+ current noise analysis was performed using the neutral Na(+) -channel blocker 6-chloro-3,5-diamino-pyrazine-2-carboxamide (CDPC) and amiloride. The analysis of CDPC-induced noise in terms of a three-state channel model revealed that Ni2+ elicits an increase in the number of open channels as well as in the spontaneous open probability. While Ni2+ had no influence on CDPC-blocker kinetics, the macroscopic and microscopic blocking kinetics of amiloride were affected. Ni2+ turned out to compete with amiloride for a putative binding site but not with CDPC. Moreover, external Na(+)--known to compete with amiloride and so producing the "self-inhibition" phenomenon--and Ni2+ exerted mutually exclusive analogous effects on amiloride kinetics. Na+ current kinetics revealed that Ni2+ prevents ENaC to be downregulated by self-inhibition. Co2+ behaved similarly to Ni2+, whereas Zn2+ did not. Attempts to disclose the chemical nature of the site reacting with Ni2+ suggested cysteine but not histidine as reaction partner.
Aguilera,
Effect of magnesium on sodium transport in toad urinary bladder.
1978, Pubmed
Aguilera,
Effect of magnesium on sodium transport in toad urinary bladder.
1978,
Pubmed
Amuzescu,
Zinc is a voltage-dependent blocker of native and heterologously expressed epithelial Na+ channels.
2003,
Pubmed
,
Xenbase
Benos,
Effects of chemical group specific reagents on sodium entry and the amiloride binding site in frog skin: evidence for separate sites.
1980,
Pubmed
Benos,
Functional domains within the degenerin/epithelial sodium channel (Deg/ENaC) superfamily of ion channels.
1999,
Pubmed
Benos,
On the mechanism of the amiloride-sodium entry site interaction in anuran skin epithelia.
1979,
Pubmed
Bevevino,
Control of sodium permeability of the outer barrier in toad skin.
1982,
Pubmed
Blazer-Yost,
Hormonal regulation of ENaCs: insulin and aldosterone.
1998,
Pubmed
,
Xenbase
Chraïbi,
Na self inhibition of human epithelial Na channel: temperature dependence and effect of extracellular proteases.
2002,
Pubmed
,
Xenbase
Cuthbert,
The role of calcium ions in the interaction of amiloride with membrane receptors.
1972,
Pubmed
De Smet,
Regulatory volume decrease in a renal distal tubular cell line (A6). I. Role of K+ and Cl-.
1995,
Pubmed
,
Xenbase
De Wolf,
Voltage-dependent Ba2+ block of K+ channels in apical membrane of frog skin.
1986,
Pubmed
Denkhaus,
Nickel essentiality, toxicity, and carcinogenicity.
2002,
Pubmed
Dulhunty,
How many cysteine residues regulate ryanodine receptor channel activity?
2000,
Pubmed
Els,
Sodium-dependent regulation of epithelial sodium channel densities in frog skin; a role for the cytoskeleton.
1993,
Pubmed
Erlij,
Effect of insulin on area and Na+ channel density of apical membrane of cultured toad kidney cells.
1994,
Pubmed
Flonta,
Cu2+ reveals different binding sites of amiloride and CDPC on the apical Na channel of frog skin.
1998,
Pubmed
Fuchs,
Current-voltage curve of sodium channels and concentration dependence of sodium permeability in frog skin.
1977,
Pubmed
Garty,
Characteristics and regulatory mechanisms of the amiloride-blockable Na+ channel.
1988,
Pubmed
Grinstein,
Nonhormonal mechanisms for the regulation of transepithelial sodium transport: the roles of surface potential and cell calcium.
1978,
Pubmed
Helman,
Blocker-related changes of channel density. Analysis of a three-state model for apical Na channels of frog skin.
1990,
Pubmed
Hillyard,
Effects of Cd++ on short-circuit current across epithelial membranes. I. Interactions with Ca++ and vasopressin on frog skin.
1976,
Pubmed
Hoshiko,
Effect of sodium on amiloride- and triamterene-induced current fluctuations in isolated frog skin.
1986,
Pubmed
Ismailov,
Identification of an amiloride binding domain within the alpha-subunit of the epithelial Na+ channel.
1997,
Pubmed
,
Xenbase
Jans,
Effects of extracellular Mg2+ on transepithelial capacitance and Na+ transport in A6 cells under different osmotic conditions.
2000,
Pubmed
Johnston,
Novobiocin stimulation of frog skin current and some metabolic consequences.
1971,
Pubmed
Kellenberger,
Epithelial sodium channel/degenerin family of ion channels: a variety of functions for a shared structure.
2002,
Pubmed
Kellenberger,
An external site controls closing of the epithelial Na+ channel ENaC.
2002,
Pubmed
,
Xenbase
Li,
Structure-activity relationship of amiloride analogs as blockers of epithelial Na channels: I. Pyrazine-ring modifications.
1985,
Pubmed
Li,
Chemical stimulation of Na transport through amiloride-blockable channels of frog skin epithelium.
1983,
Pubmed
Lindemann,
Sodium-specific membrane channels of frog skin are pores: current fluctuations reveal high turnover.
1977,
Pubmed
Lindemann,
Fluctuation analysis of sodium channels in epithelia.
1984,
Pubmed
McFarlane,
State-dependent nickel block of a high-voltage-activated neuronal calcium channel.
1998,
Pubmed
McNicholas,
Diversity of channels generated by different combinations of epithelial sodium channel subunits.
1997,
Pubmed
,
Xenbase
Palmer,
Gating of Na channels in the rat cortical collecting tubule: effects of voltage and membrane stretch.
1996,
Pubmed
Perchenet,
Pharmacological properties of Ca(V)3.2, a low voltage-activated Ca2+ channel cloned from human heart.
2000,
Pubmed
Schild,
Identification of amino acid residues in the alpha, beta, and gamma subunits of the epithelial sodium channel (ENaC) involved in amiloride block and ion permeation.
1997,
Pubmed
,
Xenbase
Scholtz,
A novel synergistic stimulation of Na+-transport across frog skin (Xenopus laevis) by external Cd2+- and Ca2+-ions.
1988,
Pubmed
,
Xenbase
Segal,
Rat ENaC expressed in Xenopus laevis oocytes is activated by cAMP and blocked by Ni(2+).
2002,
Pubmed
,
Xenbase
Sheng,
External nickel inhibits epithelial sodium channel by binding to histidine residues within the extracellular domains of alpha and gamma subunits and reducing channel open probability.
2002,
Pubmed
,
Xenbase
Smets,
Na+ dependence of single-channel current and channel density generate saturation of Na+ uptake in A6 cells.
1998,
Pubmed
Turnheim,
Kinetic analysis of the amiloride-sodium entry site interaction in rabbit colon.
1981,
Pubmed
Van Driessche,
Cyclic AMP increases electrical capacitance of apical membrane of toad urinary bladder.
1991,
Pubmed
Van Driessche,
Concentration dependence of currents through single sodium-selective pores in frog skin.
1979,
Pubmed
Van Driessche,
Transepithelial capacitance decrease reveals closure of lateral interspace in A6 epithelia.
1999,
Pubmed
Wattt,
Nickel-binding proteins.
1999,
Pubmed
Zeiske,
Chemical stimulation of Na + current through the outer surface of frog skin epithelium.
1974,
Pubmed
