کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1959518 1057940 2006 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Action Potential Morphology Influences Intracellular Calcium Handling Stability and the Occurrence of Alternans
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Action Potential Morphology Influences Intracellular Calcium Handling Stability and the Occurrence of Alternans
چکیده انگلیسی

Instability in the intracellular Ca2+ handling system leading to Ca2+ alternans is hypothesized to be an underlying cause of electrical alternans. The highly coupled nature of membrane voltage and Ca2+ regulation suggests that there should be reciprocal effects of membrane voltage on the stability of the Ca2+ handling system. We investigated such effects using a mathematical model of the cardiac intracellular Ca2+ handling system. We found that the morphology of the action potential has a significant effect on the stability of the Ca2+ handling system at any given pacing rate, with small changes in action potential morphology resulting in a transition from stable nonalternating Ca2+ transients to stable alternating Ca2+ transients. This bifurcation occurs as the alternans eigenvalue of the system changes from absolute value <1 to absolute value >1. These results suggest that the stability of the intracellular Ca2+ handling system and the occurrence of Ca2+ alternans are not dictated solely by the Ca2+ handling system itself, but are also modulated to a significant degree by membrane voltage (through its influence on sarcolemmal Ca2+ currents) and, therefore, by all ionic currents that affect membrane voltage.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 90, Issue 2, 15 January 2006, Pages 672–680
نویسندگان
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