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Expression of cardiac Na channels with appropriate physiological and pharmacological properties in Xenopus oocytes.
Krafte DS
,
Volberg WA
,
Dillon K
,
Ezrin AM
.
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The objective of this study was to determine whether the Xenopus laevis oocyte can express an exogenous cardiac Na channel that retains its normal physiological and pharmacological properties. Cardiac Na channels were expressed in oocytes following injection of RNA from guinea pig, rat, and human heart and detailed analysis was performed for guinea pig cardiac Na channels. Average current amplitudes were -351 +/- 37 nA with peak current observed at -8 +/- 1 mV. Steady-state inactivation was half-maximal at -49 +/- 0.6 mV for the expressed channels. All heart Na currents were resistant to block by tetrodotoxin compared to Na currents expressed from brain RNA with IC50 values for guinea pig, rat, and human heart of 651 nM, 931 nM, and 1.3 microM, respectively. In contrast, rat brain Na channels were blocked by tetrodotoxin with an IC50 value of 9.1 nM. In addition, the effects of the cardiac-selective agents lidocaine and DPI 201-106 were examined on Na currents expressed from brain and heart RNA. Lidocaine (10 microM) blocked cardiac Na current in a use-dependent manner but had no effect on brain Na currents. DPI 201-106 (10 microM) slowed the rate of cardiac Na channel inactivation but had no effect on inactivation of brain Na channels. These results indicate the Xenopus oocyte system is capable of synthesizing and expressing cardiac Na channels that retain normal physiological and pharmacological properties.
Bean,
Lidocaine block of cardiac sodium channels.
1983, Pubmed
Bean,
Lidocaine block of cardiac sodium channels.
1983,
Pubmed
Chandler,
Slow changes in membrane permeability and long-lasting action potentials in axons perfused with fluoride solutions.
1970,
Pubmed
Cohen,
Tetrodotoxin block of sodium channels in rabbit Purkinje fibers. Interactions between toxin binding and channel gating.
1981,
Pubmed
Colatsky,
Voltage clamp measurements of sodium channel properties in rabbit cardiac Purkinje fibres.
1980,
Pubmed
Colatsky,
Sodium channels in rabbit cardiac Purkinje fibres.
1979,
Pubmed
Cribbs,
Functional expression of the rat heart I Na+ channel isoform. Demonstration of properties characteristic of native cardiac Na+ channels.
1990,
Pubmed
,
Xenbase
Dascal,
Expression and modulation of voltage-gated calcium channels after RNA injection in Xenopus oocytes.
1986,
Pubmed
,
Xenbase
Hille,
Local anesthetics: hydrophilic and hydrophobic pathways for the drug-receptor reaction.
1977,
Pubmed
Kallen,
Primary structure and expression of a sodium channel characteristic of denervated and immature rat skeletal muscle.
1990,
Pubmed
Krafte,
Evidence for the involvement of more than one mRNA species in controlling the inactivation process of rat and rabbit brain Na channels expressed in Xenopus oocytes.
1988,
Pubmed
,
Xenbase
Lee,
Sodium current in single heart muscle cells.
1979,
Pubmed
Leonard,
Ca channels induced in Xenopus oocytes by rat brain mRNA.
1987,
Pubmed
,
Xenbase
Moorman,
Expression of single calcium channels in Xenopus oocytes after injection of mRNA from rat heart.
1987,
Pubmed
,
Xenbase
Noda,
A single point mutation confers tetrodotoxin and saxitoxin insensitivity on the sodium channel II.
1989,
Pubmed
,
Xenbase
Patlak,
Sodium channel subconductance levels measured with a new variance-mean analysis.
1988,
Pubmed
Rogart,
Molecular cloning of a putative tetrodotoxin-resistant rat heart Na+ channel isoform.
1989,
Pubmed
Romey,
Na+ channels as sites of action of the cardioactive agent DPI 201-106 with agonist and antagonist enantiomers.
1987,
Pubmed
Rudy,
Slow inactivation of the sodium conductance in squid giant axons. Pronase resistance.
1978,
Pubmed
Scholtysik,
Cardiac Na+ channel activation as a positive inotropic principle.
1989,
Pubmed
Snutch,
The use of Xenopus oocytes to probe synaptic communication.
1988,
Pubmed
,
Xenbase
Sutton,
Tetrodotoxin-sensitive voltage-dependent Na currents recorded from Xenopus oocytes injected with mammalian cardiac muscle RNA.
1988,
Pubmed
,
Xenbase
Tomaselli,
Human cardiac sodium channels expressed in Xenopus oocytes.
1990,
Pubmed
,
Xenbase
Trimmer,
Primary structure and functional expression of a mammalian skeletal muscle sodium channel.
1989,
Pubmed
,
Xenbase
