Tetrodotoxin-insensitive sodium channels in a cardiac cell line from a transgenic mouse
| Autor: | C. L. Gartside, Todd Scheuer, M E Morton, William A. Catterall, Stephen D. Hauschka, Adrian Sculptoreanu |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
medicine.medical_specialty
Physiology Sodium 8-Bromo Cyclic Adenosine Monophosphate chemistry.chemical_element Mice Transgenic Tetrodotoxin Biology Sodium Channels Cell Line Membrane Potentials Mice chemistry.chemical_compound 1-Methyl-3-isobutylxanthine Internal medicine Cyclic AMP medicine Animals Myocyte Membrane potential Myocardium Sodium channel Cell Membrane Electric Conductivity Isoproterenol Depolarization Cell Biology Adenosine Kinetics Endocrinology Verapamil chemistry Biophysics Protein Kinases Intracellular medicine.drug |
| Zdroj: | American Journal of Physiology-Cell Physiology. 262:C724-C730 |
| ISSN: | 1522-1563 0363-6143 |
| DOI: | 10.1152/ajpcell.1992.262.3.c724 |
| Popis: | The electrophysiological properties of a cardiac cell line (MCM1) originating from a transgenic mouse were characterized. The dominant current in these cells is a sodium current that is insensitive to concentrations of tetrodotoxin (TTX) up to 100 microM. It activates and inactivates rapidly with half-maximal activation at -40 mV and half-maximal inactivation at -79 mV. This sodium current is reduced by agents that increase intracellular adenosine 3',5'-cyclic monophosphate (cAMP) and activate cAMP-dependent protein kinase including isoproterenol, 8-bromo-cAMP, and isobutylmethylxanthine. The phenylalkylamine desmethoxyverapamil blocks the TTX-insensitive sodium current in MCM1 cells in both tonic and use-dependent fashion. Membrane depolarization enhances this block. It is proposed that the TTX-insensitive sodium current in these cells may be similar in origin to the embryonic type of TTX-insensitive sodium current described in other cardiac and skeletal muscle preparations. |
| Databáze: | OpenAIRE |
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