» Articles » PMID: 8894178

A Novel Antagonist, No. 7943, of the Na+/Ca2+ Exchange Current in Guinea-pig Cardiac Ventricular Cells

Overview
Journal Br J Pharmacol
Publisher Wiley
Specialty Pharmacology
Date 1996 Oct 1
PMID 8894178
Citations 73
Authors
Affiliations
Soon will be listed here.
Abstract

1. The effects of No. 7943 on the Na+/Ca2+ exchange current and on other membrane currents were investigated in single cardiac ventricular cells of guinea-pig with the whole-cell voltage-clamp technique. 2. No. 7943 at 0.1-10 microM suppressed the outward Na+/Ca2+ exchange current in a concentration-dependent manner. The suppression was reversible and the IC50 value was approximately 0.32 microM. 3. No. 7943 at 5-50 microM suppressed also the inward Na+/Ca2+ exchange current in a concentration-dependent manner but with a higher IC50 value of approximately 17 microM. 4. In a concentration-response curve, No. 7943 raised the K(m)Ca2+ value, but did not affect the Imax value, indicating that No. 7943 is a competitive antagonist with external Ca2+ for the outward Na+/ Ca2+ exchange current. 5. The voltage-gated Na+ current, Ca2+ current and the inward rectifier K+ current were also inhibited by No. 7943 with IC50S of approximately 14, 8 and 7 microM, respectively. 6. In contrast to No. 7943, 3', 4'-dichlorobenzamil (DCB) at 3-30 microM suppressed the inward Na+/Ca2+ exchange current with IC50 of 17 microM, but did not affect the outward exchange current at these concentrations. 7. We conclude that No. 7943 inhibits the outward Na+/Ca2+ exchange current more potently than any other currents as a competitive inhibitor with external Ca2+. This effect is in contrast to DCB which preferentially inhibits the inward rather than the outward Na+/Ca2+ exchange current.

Citing Articles

Structural mechanisms of PIP activation and SEA0400 inhibition in human cardiac sodium-calcium exchanger NCX1.

Xue J, Zeng W, John S, Attiq N, Ottolia M, Jiang Y bioRxiv. 2024; .

PMID: 39677781 PMC: 11643123. DOI: 10.1101/2024.12.05.627058.


The Sodium-Calcium Exchanger Controls the Membrane Potential of AFT024: A Mesenchymal Stem Cell Hematopoietic Niche Forming Line.

Potier-Cartereau M, Gautier M, Ravalet N, Ducrocq E, Hamard S, LeGuennec J Bioelectricity. 2024; 4(2):103-107.

PMID: 39350778 PMC: 11441364. DOI: 10.1089/bioe.2022.0015.


Calcium-Dependent Interplay of Lithium and Tricyclic Antidepressants, Amitriptyline and Desipramine, on -methyl-D-aspartate Receptors.

Boikov S, Sibarov D, Stepanenko Y, Karelina T, Antonov S Int J Mol Sci. 2022; 23(24).

PMID: 36555818 PMC: 9787943. DOI: 10.3390/ijms232416177.


The Role of the Na/Ca Exchanger in Aberrant Intracellular Ca in Cardiomyocytes of Chagas-Infected Rodents.

Lopez J, Linares N, Adams J, Mijares A Front Cell Infect Microbiol. 2022; 12:890709.

PMID: 35903196 PMC: 9318578. DOI: 10.3389/fcimb.2022.890709.


The Na/Ca Exchanger 3 Is Functionally Coupled With the Na1.6 Voltage-Gated Channel and Promotes an Endoplasmic Reticulum Ca Refilling in a Transgenic Model of Alzheimer's Disease.

Piccialli I, Ciccone R, Secondo A, Boscia F, Tedeschi V, de Rosa V Front Pharmacol. 2021; 12:775271.

PMID: 34955845 PMC: 8692738. DOI: 10.3389/fphar.2021.775271.


References
1.
Blaustein M, Russell J . Sodium-calcium exchange and calcium-calcium exchange in internally dialyzed squid giant axons. J Membr Biol. 1975; 22(3-4):285-312. DOI: 10.1007/BF01868176. View

2.
Li Z, Nicoll D, Collins A, Hilgemann D, Filoteo A, Penniston J . Identification of a peptide inhibitor of the cardiac sarcolemmal Na(+)-Ca2+ exchanger. J Biol Chem. 1991; 266(2):1014-20. View

3.
Reeves J, Sutko J . Competitive interactions of sodium and calcium with the sodium-calcium exchange system of cardiac sarcolemmal vesicles. J Biol Chem. 1983; 258(5):3178-82. View

4.
Niggli E, Lederer W . Molecular operations of the sodium-calcium exchanger revealed by conformation currents. Nature. 1991; 349(6310):621-4. DOI: 10.1038/349621a0. View

5.
Bersohn M, Philipson K, Weiss R . Lysophosphatidylcholine and sodium-calcium exchange in cardiac sarcolemma: comparison with ischemia. Am J Physiol. 1991; 260(3 Pt 1):C433-8. DOI: 10.1152/ajpcell.1991.260.3.C433. View