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	Provedor de dados Biol. Res. (4) BJMBR (1) Neotropical Ichthyology (1) Autor BARRIENTOS,GENARO (1) BELTRÁN,MARIANELA (1) Costa,Monica Jones (1) DIFRANCO,MARINO (1) GYÖRKE,INNA (1) GYÖRKE,SANDOR (1) HIDALGO,CECILIA (1) Kalinin,Ana Lúcia (1) Maier,L.S. (1) Rantin,Francisco Tadeu (1) RÍOS,EDUARDO (1) TERENTYEV,DMITRY (1) VERGARA,JULIO L (1) VIATCHENKO-KARPINSKI,SERGE (1) WILLIAMS,SIMON C (1) ZHOU,JINGSONG (1) Mais... Palavra-chave Excitation-contraction coupling (6) Sarcoplasmic reticulum (3) Calcium-induced calcium release (2) Ryanodine receptor (2) Arrhythmia (1) Ca2+ sparks (1) CaM kinase (1) Caffeine (1) Calcium (1) Calcium microdomains (1) Calcium release kinetics (1) Calcium transients (1) Calcium-binding proteins (1) Calmodulin (1) Calsequestrin (1) Confocal spot detection (1) Frog skeletal muscle (1) Heart (1) Ryanodine (1) Ryanodine receptors (1) Mais... Tipo do documento Journal article (4) Info:eu-repo/semantics/article (2) Ano 2009 (1) 2006 (2) 2005 (1) 2004 (2) País Chile (4) Brazil (2) Idioma Inglês (6)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 6 Primeira ... 1 ... Última Modulation of sarcoplasmic reticulum calcium release by calsequestrin in cardiac myocytes Biol. Res. GYÖRKE,SANDOR; GYÖRKE,INNA; TERENTYEV,DMITRY; VIATCHENKO-KARPINSKI,SERGE; WILLIAMS,SIMON C. Calsequestrin (CASQ2) is a high capacity Ca-binding protein expressed inside the sarcoplasmic reticulum (SR). Mutations in the cardiac calsequestrin gene (CASQ2) have been linked to arrhythmias and sudden death induced by exercise and emotional stress. We have studied the function of CASQ2 and the consequences of arrhythmogenic CASQ2 mutations on intracellular Ca signalling using a combination of approaches of reverse genetics and cellular physiology in adult cardiac myocytes. We have found that CASQ2 is an essential determinant of the ability of the SR to store and release Ca2+ in cardiac muscle. CASQ2 serves as a reservoir for Ca2+ that is readily accessible for Ca2+-induced Ca2+ release (CICR) and also as an active Ca2+ buffer that modulates the local... Tipo: Journal article Palavras-chave: Excitation-contraction coupling; Calcium-induced calcium release; Ryanodine receptor; Calsequestrin; Arrhythmia. Ano: 2004 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000400014 Fast kinetics of calcium dissociation from calsequestrin Biol. Res. BELTRÁN,MARIANELA; BARRIENTOS,GENARO; HIDALGO,CECILIA. We measured the kinetics of calcium dissociation from calsequestrin in solution or forming part of isolated junctional sarcoplasmic reticulum membranes by mixing calsequestrin equilibrated with calcium with calcium-free solutions in a stopped-flow system. In parallel, we measured the kinetics of the intrinsic fluorescence changes that take place following calcium dissociation from calsequestrin. We found that at 25ºC calcium dissociation was 10-fold faster for calsequestrin attached to junctional membranes (k = 109 s-1) than in solution. These results imply that calcium dissociation from calsequestrin in vivo is not rate limiting during excitation-contraction coupling. In addition, we found that the intrinsic fluorescence decrease for calsequestrin in... Tipo: Journal article Palavras-chave: Calcium-binding proteins; Ryanodine receptors; Sarcoplasmic reticulum; Calcium release kinetics; Excitation-contraction coupling; Skeletal and cardiac muscle. Ano: 2006 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000300011 Modulation by caffeine of calcium-release microdomains in frog skeletal muscle fibers Biol. Res. VERGARA,JULIO L; DIFRANCO,MARINO. The effects of caffeine on the process of excitation-contraction coupling in amphibian skeletal muscle fibers were investigated using the confocal spot detection technique. This method permits to carefully discriminate between caffeine effects on the primary sources of Ca2+ release at the Z-lines where the triads are located and secondary actions on other potential Ca Release sources. Our results demonstrate that 0.5 mM caffeine potentiates and prolongs localized action-potential evoked Ca2+ transients recorded at the level of the Z-lines, but that 1mM only prolongs them. The effects at both doses are reversible. At the level of the M-line, localized Ca2+ transients displayed more variability in the presence of 1 mM caffeine than in control conditions. At... Tipo: Journal article Palavras-chave: Excitation-contraction coupling; Caffeine; Confocal spot detection; Calcium transients; Frog skeletal muscle; Calcium microdomains. Ano: 2006 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000300017 Control of dual isoforms of Ca2+ release channels in muscle Biol. Res. RÍOS,EDUARDO; ZHOU,JINGSONG. Here we compare excitation-contraction coupling in single muscle cells of frogs and rats. Because amphibians have isoform 3 (or b) of the ryanodine receptor/Ca2+ release channel, in addition to 1 (a), which is also present in the mammal, any extra feature present in the frog may in principle be attributed to isoform 3. Ca2+ release under voltage clamp depolarization has a peak and a steady phase in both taxonomic classes, but the peak is more marked in the frog, where the ratio of amplitudes of the two phases is voltage-dependent. This dependence is a hallmark of CICR. Confocal imaging identified Ca2+ sparks in the frog, but not in the voltage-clamped rat cells. Because Ca2+ sparks involve CICR both observations indicate that the contribution of CICR is... Tipo: Journal article Palavras-chave: Excitation-contraction coupling; Sarcoplasmic reticulum; Ca2+ sparks; Ryanodine receptor; Calcium-induced calcium release. Ano: 2004 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000400012 CaMKIIdelta overexpression in hypertrophy and heart failure: cellular consequences for excitation-contraction coupling BJMBR Maier,L.S.. Ca/calmodulin-dependent protein kinase IIdelta (CaMKIIdelta) is the predominant isoform in the heart. During excitation-contraction coupling (ECC) CaMKII phosphorylates several Ca-handling proteins including ryanodine receptors (RyR), phospholamban, and L-type Ca channels. CaMKII expression and activity have been shown to correlate positively with impaired ejection fraction in the myocardium of patients with heart failure and CaMKII has been proposed to be a possible compensatory mechanism to keep hearts from complete failure. However, in addition to these acute effects on ECC, CaMKII was shown to be involved in hypertrophic signaling, termed excitation-transcription coupling (ETC). Thus, animal models have shown that overexpression of nuclear isoform... Tipo: Info:eu-repo/semantics/article Palavras-chave: Calcium; Calmodulin; CaM kinase; Excitation-contraction coupling; Heart. Ano: 2005 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000900002 Differences in Ca2+-management between the ventricle of two species of neotropical teleosts: the jeju, Hoplerythrinus unitaeniatus (Spix & Agassiz, 1829), and the acara, Geophagus brasiliensis (Quoy & Gaimard, 1824) Neotropical Ichthyology Costa,Monica Jones; Rantin,Francisco Tadeu; Kalinin,Ana Lúcia. This study analyzed the physiological role of the cardiac sarcoplasmic reticulum (SR) of two neotropical teleosts, the jeju, Hoplerythrinus unitaeniatus (Erythrinidae), and the acara, Geophagus brasiliensis (Cichlidae). While the in vivo heart frequency (fH - bpm) of acara (79.6 ± 6.6) was higher than that of the jeju (50.3 ± 2.7), the opposite was observed for the ventricular inotropism (Fc - mN/mm²) at 12 bpm (acara = 28.66 ± 1.86 vs. jeju = 36.09 ± 1.67). A 5 min diastolic pause resulted in a strong potentiation of Fc (≅ 90%) of strips from jeju, which was completely abolished by ryanodine. Ryanodine also resulted in a ≅ 20% decrease in the Fc developed by strips from jeju at both subphysiological (12 bpm) and physiological (in vivo) frequencies.... Tipo: Info:eu-repo/semantics/article Palavras-chave: Excitation-contraction coupling; Ryanodine; Sarcoplasmic reticulum; Ventricle strips. Ano: 2009 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252009000300015 Registros recuperados: 6 Primeira ... 1 ... Última

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