The voltage dependence of the intracellular Ca2+ transients was measured in single rat ventricular myocytes with the fluorescent Ca2+ indicator dye fura-2. The whole-cell voltage clamp technique was used to measure the membrane current, and 0.9 mM fura-2 was loaded into the cell by including it in the dialyzing solution of the patch electrode. A mechanical light chopper operating at 1200 Hz was...

هدف: هدف پژوهش حاضر، تبیین الگوی برنامه درسی سواد رسانه‌ای در دوره ابتدایی نظام آموزش و پرورش است.مواد روش‌ها: رویکرد حاکم بر کیفی با استفاده از روش نظریه داده بنیاد انجام شده است. شرکت‌کنندگان این پژوهش، متخصصان صاحب‌نظران حوزه رسانه هستند که نمونه‌گیری هدفمند، 15 نفر آنان مصاحبه شد. ابزار گردآوری داده‌ها، نیمه‌ساختارمند بود تعداد محقق به اشباع نظری رسید.بحث نتیجه‌گیری: برای تجزیه تحلیل داده‌ه...

The goal of this study was to examine the relationship between Ca2+ entry through L-type Ca2+ channels and local [Ca2+]i transients (Ca2+ sparks) in single rat cardiac ventricular cells. L-type Ca2+ channels were activated by depolarization of cell-attached membrane patches, and [Ca2+]i was measured simultaneously as fluo 3 fluorescence using laser scanning confocal microscopy. Patch depolariza...

The aim of this study was to investigate the role Ca2+ in process calpain-2 becoming associated myofibrils and potential myofibril-bound calpain degrade myofibrillar proteins. Different concentrations were applied mixed with partially purified calpain-2. induced binding a concentration-dependent manner. half-maximal requirements for proteolysis 0.60 mM 0.29 mM, respectively. To proteolytic acti...

A variety of reagents (local anesthetics, phenothiazines, ruthenium red, ryanodine, dicyclohexylcarbodiimide, R 24571) inhibit Ca2+-induced Ca2+ release from purified canine cardiac sarcoplasmic reticulum (SR). Most of these compounds also increase the rate of net Ca2+ uptake by cardiac SR while moderately inhibiting Ca2+-dependent ATP hydrolysis, and together these two effects produce increase...

The peritrich ciliate Vorticella sp. exhibits cellular contraction of an all-or-nothing type in response to a mechanical stimulus. Many authors have suggested that the contraction may be controlled by the cytosolic level of Ca2+, since glycerol-extracted Vorticella contracts when Ca2+ is added to the external solution. However, no direct evidence for the increase in cytosolic [Ca2+] has yet bee...

The demonstration that F1FO (F)-ATP synthase and adenine nucleotide translocase (ANT) can form Ca2+-activated, high-conductance channels in the inner membrane of mitochondria from a variety eukaryotes led to renewed interest permeability transition (PT), increase mediated by PT pore (PTP). is Ca2+-dependent mitochondrial whose function underlying molecular mechanisms have challenged scientists ...

Bovine chromaffin-granule ghosts accumulate 45Ca2+ in a temperature- and osmotic-shock-sensitive process; the uptake is saturable, with Km 38 microM and Vmax. 28 nmol/min per mg at 37 degrees C. Entry occurs by exchange with Ca2+ bound to the inner surface of the membrane. It is inhibited non-competitively by Na+, La3+ and Ruthenium Red (Ki 10.7 mM, 7 microM and 2 microM respectively), and comp...

The regulatory protein phospholamban exerts a physiological inhibitory effect on the sarcoplasmic reticulum (SR) Ca2+ pump that is relieved with phosphorylation. We have studied the subcellular properties of intracellular Ca2+([Ca2+]i) transients in ventricular myocytes isolated from wild-type (WT) and phospholamban-deficient (PLB-KO) mice. In PLB-KO myocytes, steady-state twitch [Ca2+]itransie...

The amount of Ca2+ released from the sarcoplasmic reticulum (SR) is a principal determinant of cardiac contractility. Normally, the SR Ca2+ stores are mobilized through the mechanism of Ca2+-induced Ca2+ release (CICR). In this process, Ca2+ enters the cell through plasmalemmal voltage-dependent Ca2+ channels to activate the Ca2+ release channels in the SR membrane. Consequently, the control of...