Two structurally distinct calcium storage sites in rat cardiac sarcoplasmic reticulum: an electron microprobe analysis study.
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چکیده
منابع مشابه
Two structurally distinct calcium storage sites in rat cardiac sarcoplasmic reticulum: an electron microprobe analysis study.
The elemental composition of subcellular organelles in resting rat papillary muscle was measured by electron probe x-ray microanalysis of cryosections of flash-frozen tissue. Nonmitochondrial electron-dense structures (50-100 nm in diameter) with a phosphorous concentration larger than 375 mmol/kg dry wt were identified in the interfibrillar spaces of the I band region. They were not visible in...
متن کاملSarcoplasmic reticulum calcium leak and cardiac arrhythmias.
Ventricular arrhythmias deteriorating into sudden cardiac death are a major cause of mortality worldwide. The recent linkage of a genetic form of cardiac arrhythmia to mutations in the gene encoding RyR2 (ryanodine receptor 2) has uncovered an important role of this SR (sarcoplasmic reticulum) calcium release channel in triggering arrhythmias. Mutant RyR2 channels give rise to spontaneous relea...
متن کاملCalcium release and ionic changes in the sarcoplasmic reticulum of tetanized muscle: an electron-probe study
Approximately 60-70% of the total fiber calcium was localized in the terminal cisternae (TC) in resting frog muscle as determined by electron-probe analysis of ultrathin cryosections. During a 1.2 s tetanus, 59% (69 mmol/kg dry TC) of the calcium content of the TC was released, enough to raise total cytoplasmic calcium concentration by approximately 1 mM. This is equivalent to the concentration...
متن کاملNADH oxidase activity of rat cardiac sarcoplasmic reticulum regulates calcium-induced calcium release.
NADH and Ca2+ have important regulatory functions in cardiomyocytes related to excitation-contraction coupling and ATP production. To elucidate elements of these functions, we examined the effect of NADH on sarcoplasmic reticulum (SR) Ca2+ release and the mechanisms of this regulation. Physiological concentrations of cytosolic NADH inhibited ryanodine receptor type 2 (RyR2)-mediated Ca2+-induce...
متن کاملDynamic Calcium Movement in Cardiac Sarcoplasmic Reticulum during Release
METHODS Cell isolation Single ventricular myocytes were isolated from New Zealand White rabbits using standard enzymatic techniques. All procedures were performed in accordance with the Guide for the Care and Use of Laboratory Animals published by the US National Institutes of Health and approved by the Institutional Animal Care and Use Committee. Animals were anaesthetized with sodium pentobar...
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ژورنال
عنوان ژورنال: Circulation Research
سال: 1988
ISSN: 0009-7330,1524-4571
DOI: 10.1161/01.res.63.6.1060