Skeletal muscle Ca2+ channels

Avila-Sakar, Agustin; Cota, Gabriel; Gamboa-Aldeco, R.; Garcı́a, Jesús; Huerta, Miguel; Muñı́z, Jesús; Stefani, Enrico

doi:10.1007/bf01753649

Cited by 28 publications

(14 citation statements)

References 46 publications

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“…Several million Ca ions/ sec can enter cells through open Ca channels. Ca channels are important in supplying Ca to many types of cells, particularly to excitatory cells such as muscle and nerve, where they are postulated to play a role in excitation-contraction coupling and neurotransmitter release, respectively (for reviews, see Reuter, 1983;Tsien, 1983;Avila-Sakar et al, 1986;McCleskey et al, 1986;Miller, 1987a;Morad & Cleemann, 1987). Ca channels are also present in secretory cells (Baker, Knight & Knight, 1981;Fenwick, Marty & Neher, 1982;Luini et al, 1986) and other nonexcitable cells such as lymphocytes (Fukushima & Hagiwara, 1983), sperm (Kazazoglou et al, 1985) and neutrophils (von Tscharner et al, 1986), and probably even in plant cells (Graziana et al, 1988) where regulation of Ca entry is also important for cell function.…”

Section: Introductionmentioning

confidence: 99%

Calcium channels: Molecular pharmacology, structure and regulation

1988

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Section: Introductionmentioning

confidence: 99%

Calcium channels: Molecular pharmacology, structure and regulation

1988

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“…In skeletal muscle, I Ca is not believed to undergo Ca 2ϩ -dependent inactivation (1,40,45). The currents obtained by expression of the Fg␣1S had a rapid phase of decay, to ϳ75% of their peak amplitude after 100 ms, that was clearly greater in Ca 2ϩ than Ba 2ϩ .…”

Section: Current-dependent Inactivation Of Expressed Channels-ltype Camentioning

confidence: 96%

Molecular Cloning and Functional Expression of a Skeletal Muscle Dihydropyridine Receptor from Rana catesbeiana

Zhou¹,

Cribbs²,

Yi³

et al. 1998

Journal of Biological Chemistry

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In skeletal muscle the dihydropyridine receptor is the voltage sensor for excitation-contraction coupling and an L-type Ca 2؉ channel. We cloned a dihydropyridine receptor (named Fg␣1S) from frog skeletal muscle, where excitation-contraction coupling has been studied most extensively. Fg␣1S contains 5600 base pairs coding for 1688 amino acids. It is highly homologous with, and of the same length as, the C-truncated form predominant in rabbit muscle. The primary sequence has every feature needed to be an L-type Ca 2؉ channel and a skeletal-type voltage sensor. Currents expressed in tsA201 cells had rapid activation (5-10 ms half-time) and Ca 2؉ -dependent inactivation. Although functional expression of the full Fg␣1S was difficult, the chimera consisting of Fg␣1S domain I in the rabbit cardiac Ca channel had high expression and a rapidly activating current. The slow native activation is therefore not determined solely by the ␣1 subunit sequence. Its Ca 2؉ -dependent inactivation strengthens the notion that in rabbit skeletal muscle this capability is inhibited by a C-terminal stretch (Adams, B., and Tanabe, T. (1997) J. Gen. Physiol. 110, 379 -389). This molecule constitutes a new tool for studies of excitation-contraction coupling, gating, modulation, and gene expression.

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“…In adult frog muscle a fast calcium cwrent has been described which activates rapidly but does not show inactivation with maintained depolarizations (Cota and Stefani 1986;Garcia and Stefani 1987). This current is particularly labile and tends to "rundown" in standard recording solution (Cota and Stefani 1986;Garcia and Stefani 1987). The g u p s e of the present study was to examine the types of calcium current present in Xereopus embryonic muscle cells in culture.…”

Section: Introductionmentioning

confidence: 98%

“…In embryonic rat myotuks this current activates and inactivates rapidly and is not sensitive to dihydropyridines (Beam et al 1986;Cognard et al 1986). In adult frog muscle a fast calcium cwrent has been described which activates rapidly but does not show inactivation with maintained depolarizations (Cota and Stefani 1986;Garcia and Stefani 1987). This current is particularly labile and tends to "rundown" in standard recording solution (Cota and Stefani 1986;Garcia and Stefani 1987).…”

Section: Introductionmentioning

confidence: 98%

Calcium current in embryonic Xenopus muscle cells in culture

Moody-Corbett¹,

Gilbert²,

Akbarali³

et al. 1989

Can. J. Physiol. Pharmacol.

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We have investigated the appearance of calcium current in Xenopus muscle cells in 1- to 6-day-old cultures. Whole cell currents were recorded using a patch-clamp amplifier with sodium and potassium replaced with tetraethylammonium and cesium, respectively, and BaCl2 used in place of CaCl2. When the muscle membrane was depolarized above -30 mV, a slow inward current was activated, the current reached a peak amplitude near 0 mV, and an outward current became apparent above +10 mV. This slow current was enhanced by adding barium or Bay K 8644 to the extracellular recording solution and was blocked by the addition of cobalt, cadmium, or the dihydropyridines nifedipine or (+)PN 200-110. Taken together these results indicate the presence of an inward calcium current mediated through L-type channels. Thirty-one percent of the cells examined on the first day in culture showed no discernible slow inward current; however, as the age of the culture increased, all cells showed slow inward current and there was an increase in the amplitude of the current. A small proportion of the muscle cells (5 out of 34) also showed a fast activating and inactivating inward current. This current, which activated at more hyperpolarized potentials (-40 mV) was only present when 5 mM ATP was included in the internal recording solution. It also appeared to be mediated through a calcium channel but not a dihydropyridine, sensitive channel.

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Skeletal muscle Ca2+ channels

Cited by 28 publications

References 46 publications

Calcium channels: Molecular pharmacology, structure and regulation

Calcium channels: Molecular pharmacology, structure and regulation

Molecular Cloning and Functional Expression of a Skeletal Muscle Dihydropyridine Receptor from Rana catesbeiana

Calcium current in embryonic Xenopus muscle cells in culture

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