کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10954223 1097851 2009 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Local control of Ca2+-induced Ca2+ release in mouse sinoatrial node cells
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Local control of Ca2+-induced Ca2+ release in mouse sinoatrial node cells
چکیده انگلیسی
Emerging evidence from large animal models implicates Ca2+ regulation, particularly intracellular sarcoplasmic reticulum (SR) Ca2+ release, as essential for sinoatrial node (SAN) automaticity. However, despite the apparent importance of SR Ca2+ release to SAN cell function it is uncertain how SR Ca2+ release is controlled in SAN cells from mouse. Understanding mouse SAN SR Ca2+ release mechanism will allow improved understanding of results in studies on SAN from genetic mouse models of Ca2+ homeostatic proteins. Here we investigated the functional relationship between sarcolemmal Ca2+ influx and SR Ca2+ release at the level of single SAN cell, using simultaneous patch-clamp current recording and high resolution confocal Ca2+ imaging techniques. In mouse SAN cells, both Ca2+ channel currents and triggered SR Ca2+ transients displayed bell-shaped, graded function with the membrane potential. Moreover, the gain function for Ca2+-induced Ca2+ release (CICR) displayed a monotonically decreasing function with strong voltage dependence, consistent with a “local control” mechanism for CICR. In addition, we observed numerous discrete Ca2+ sparks at the voltage range of diastolic depolarization, in sharp contrast to the much lower frequency of sparks observed at resting potentials. We concluded that the “local control” mechanism of CICR is responsible for both local Ca2+ release during diastolic depolarization and the synchronized Ca2+ transients observed during action potential in SAN cells.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular and Cellular Cardiology - Volume 47, Issue 5, November 2009, Pages 706-715
نویسندگان
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