7 research outputs found
NCX in myocytes from the area adjacent to MI.
<p>A. NCX function was measured as the tail current upon repolarization to β70 mV (arrow) after a step to +10 mV in CTRL and MI. B. Averaged NCX current density in CTRL (N<sub>pigs</sub>β=β9, n<sub>cells</sub>β=β30) and MI (N<sub>pigs</sub>β=β7, n<sub>cells</sub>β=β19), with [Ca<sup>2+</sup>]<sub>i</sub> measured simultaneously. * denotes P<0.05.</p
Effect of remodeling in the area adjacent to MI on Ca<sup>2+</sup> sparks.
<p>A. Representative line scan image of Ca<sup>2+</sup> spark recording in MI. The types of release areas are marked in blue and red for early and delayed release areas respectively. The artifact region (marked by β) was excluded for analysis. B. Whole-cell spark frequency and morphology in CTRL (N<sub>pigs</sub>β=β12, n<sub>cells</sub>β=β41) and MI (N<sub>pigs</sub>β=β7, n<sub>cells</sub>β=β33). C. Spark mass, calculated by amplitude*width*duration, and spark-mediated Ca<sup>2+</sup> leak, calculated by spark frequency*spark mass, in CTRL (N<sub>pigs</sub>β=β12, n<sub>cells</sub>β=β41) and MI (N<sub>pigs</sub>β=β7, n<sub>cells</sub>β=β33). D. SR Ca<sup>2+</sup> content as Β΅moles/L accessible cytosol, in CTRL (N<sub>pigs</sub>β=β4, n<sub>cells</sub>β=β15) and MI (N<sub>pigs</sub>β=β4, n<sub>cells</sub>β=β12). * denotes P<0.05.</p
Ca<sup>2+</sup> removal by NCX during caffeine application.
<p>A. Example of current and [Ca<sup>2+</sup>]<sub>i</sub> transient recording obtained during the last conditioning pulse from -70 to +10 mV and caffeine application (left). The decay of the current was fit by a 1- or 2-exponential according to the goodness of fit (R<sup>2</sup>>0.95) and with the 2 amplitudes being negative. The right panel is a typical example of a 2-exponential decay in a CTRL myocyte. B. Example of monophasic I<sub>NCX</sub> decay (left) and mean data on incidence of biphasic decay (middle). The percentage of cells better fit by a biphasic exponential was significantly higher in CTRL than in MI (CTRL, N<sub>pigs</sub>β=β4, n<sub>cells</sub>β=β17; MI, N<sub>pigs</sub>β=β4, n<sub>cells</sub>β=β12, P<0.05). In addition, Tau of fast component of I<sub>NCX</sub> decay tended to be faster in CTRL than in MI (right, CTRL, N<sub>pigs</sub>β=β4, n<sub>cells</sub>β=β8, <i>vs</i>. MI, N<sub>pigs</sub>β=β2, n<sub>cells</sub>β=β4, Pβ=βNS). * denotes P<0.05.</p
Subcellular spark properties in myocytes from the area adjacent to MI.
<p>A. Spark frequency, and, B, duration in early vs. delayed release areas in MI, with the MI-dependent change in each area (CTRL N<sub>pigs</sub>β=β12, n<sub>cells</sub>β=β41 vs. MI N<sub>pigs</sub>β=β7, n<sub>cells</sub>β=β33). C. Example of long spark in 3D and fraction of cells showing long-lasting sparks (>47.6 ms) in CTRL (24/43 cells with long sparks) and MI (22/31 cells with long sparks). * denotes P<0.05.</p
Effect of sarcolemmal fluxes on spark frequency and duration.
<p>A. Effect of NCX block by 5 mM nickel on spark frequency and duration in early (left) and delayed (right) release areas in CTRL cardiomyocytes (N<sub>pigs</sub>β=β3, n<sub>cells</sub>β=β7). B. Effect of I<sub>CaL</sub> block by 50 Β΅M cadmium on spark frequency and duration in early (left) and delayed (right) release areas in CTRL cardiomyocytes (N<sub>pigs</sub>β=β2, n<sub>cells</sub>β=β9). * denotes P<0.05.</p
Effect of proximity of TTs to RyR on spontaneous Ca<sup>2+</sup> sparks.
<p>A. Typical example of a line scan image during and after 1 Hz stimulation. After loading the SR with conditioning pulses from β70 to +10 mV at 1 Hz, stimulation was stopped and 15 seconds of diastole were recorded for Ca<sup>2+</sup> sparks. Sparks were assigned to early (blue) and delayed (red) release areas corresponding to their position on the scan line. B. Spark frequency and morphology in early vs. delayed release areas in CTRL pigs (N<sub>pigs</sub>β=β12, n<sub>cells</sub>β=β41). * denotes P<0.05.</p
Modulation of Ca<sup>2+</sup> sparks with TT loss during culture.
<p>A. Representative confocal images of TT staining with di-8-ANEPPS (left) and RyR staining (right) after 48 hours of culture. B. Representative line scan image of Ca<sup>2+</sup> spark protocol in CULT. The type of release areas is marked in blue and red for early and delayed release areas respectively. C. Comparison of spark duration in early (left) and delayed (right) release areas in CTRL (N<sub>pigs</sub>β=β7, n<sub>cells</sub>β=β29) vs. CULT (N<sub>pigs</sub>β=β7, n<sub>cells</sub>β=β14). D. Fraction of cells showing long-lasting sparks (>47.6 ms) in CTRL (17/35 cells with long sparks) and CULT (10/15 cells with long sparks). E. NCX current density in CTRL (N<sub>pigs</sub>β=β4, n<sub>cells</sub>β=β14) and CULT (N<sub>pigs</sub>β=β4, n<sub>cells</sub>β=β7). * denotes P<0.05.</p