Gating of skeletal and cardiac muscle sodium channels in mammalian cells
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چکیده
منابع مشابه
Structural basis of differences in isoform-specific gating and lidocaine block between cardiac and skeletal muscle sodium channels.
Voltage-gated Na(+) channels underlie rapid conduction in heart and skeletal muscle. Cardiac sodium channels open and close over more negative potentials than do skeletal muscle sodium channels; heart channels are also more sensitive to lidocaine block. The structural basis of these differences is poorly understood. We mutated nine isoform-specific micro1 (rat skeletal muscle) channel residues ...
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Ca2+-activated K+ channels from rat muscle transverse tubule membranes were inserted into planar phospholipid bilayers, and the activation of these channels by Ca2+ was studied. On the cytoplasmic side of the channel, calcium ions (in the range 10-100 mumol l-1) increase the opening probability of the channel in a graded way. This 'activation curve' is sigmoid, with an average Hill coefficient ...
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Voltage-dependent gating was investigated in a recombinant human skeletal muscle Cl- channel, hCIC-1, heterologously expressed in human embryonic kidney (HEK-293) cells. Gating was found to be mediated by two qualitatively distinct processes. One gating step operates on a microsecond time scale and involves the rapid rearrangement of two identical intramembranous voltage sensors, each consistin...
متن کاملSodium channel gating currents in frog skeletal muscle
Charge movements similar to those attributed to the sodium channel gating mechanism in nerve have been measured in frog skeletal muscle using the vaseline-gap voltage-clamp technique. The time course of gating currents elicited by moderate to strong depolarizations could be well fitted by the sum of two exponentials. The gating charge exhibits immobilization: at a holding potential of -90 mV th...
متن کاملCurrent-dependent gating of single cardiac sodium channels?
Based on studies of differences in physicochemical properties of antagonists and agonists of ionic channels it has been proposed that the magnitude of the elementary currents might influence the gating properties of ionic channel (personal communication) who reported that in inwardly rectifying potassium channels increased unitary currents induced prolonged single channel openings. A similar fi...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 1999
ISSN: 0022-3751
DOI: 10.1111/j.1469-7793.1999.425ae.x