Role of Cytosolic Calcium Diffusion and Sarcolemmal T-Type Calcium Current in Triggered Activity in Purkinje Cells: A Simulation Study

Heart Rhythm ◽  
2011 ◽  
Vol 8 (11) ◽  
pp. 1821
Author(s):  
M. Deo ◽  
S.V. Pandit ◽  
R. Vaidyanathan ◽  
R. OConnell ◽  
M. Milstein ◽  
...  
Keyword(s):  
Purkinje Cells ◽  
Simulation Study ◽  
Calcium Current ◽  
Cytosolic Calcium ◽  
Triggered Activity ◽  
Calcium Diffusion

scholarly journals Role of Cytosolic Calcium Diffusion in Murine Cardiac Purkinje Cells

2016 ◽  
Vol 10s1 ◽  
pp. CMC.S39705
Author(s):  
Bijay Limbu ◽  
Kushal Shah ◽  
Seth H. Weinberg ◽  
Makarand Deo
Keyword(s):  
Purkinje Cells ◽  
Ventricular Myocytes ◽  
Ionic Current ◽  
Cytosolic Calcium ◽  
Diffusion Waves ◽  
Cardiac Purkinje Cells ◽  
Calcium Diffusion ◽  
Intracellular Ca ◽  
Diffusion Rates

Cardiac Purkinje cells (PCs) are morphologically and electrophysiologically different from ventricular myocytes and, importantly, exhibit distinct calcium (Ca2+) homeostasis. Recent studies suggest that PCs are more susceptible to action potential (AP) abnormalities than ventricular myocytes; however, the exact mechanisms are poorly understood. In this study, we utilized a detailed biophysical mathematical model of a murine PC to systematically examine the role of cytosolic Ca2+ diffusion in shaping the AP in PCs. A biphasic spatiotemporal Ca2+ diffusion process, as recorded experimentally, was implemented in the model. In this study, we investigated the role of cytosolic Ca2+ dynamics on AP and ionic current properties by varying the effective Ca2+ diffusion rate. It was observed that AP morphology, specifically the plateau, was affected due to changes in the intracellular Ca2+ dynamics. Elevated Ca2+ concentration in the sarcolemmal region activated inward sodium-Ca2+ exchanger (NCX) current, resulting in a prolongation of the AP plateau at faster diffusion rates. Artificially clamping the NCX current to control values completely reversed the alterations in the AP plateau, thus confirming the role of NCX in modifying the AP morphology. Our results demonstrate that cytosolic Ca2+ diffusion waves play a significant role in shaping APs of PCs and could provide mechanistic insights in the increased arrhythmogeneity of PCs.

scholarly journals Simulation Study of the Structure and Phase Behavior of Ceramide Bilayers and the Role of Lipid Headgroup Chemistry

2013 ◽  
Vol 9 (11) ◽  
pp. 5116-5126 ◽  
Author(s):  
Shan Guo ◽  
Timothy C. Moore ◽  
Christopher R. Iacovella ◽  
L. Anderson Strickland ◽  
Clare McCabe
Keyword(s):  
Phase Behavior ◽  
Simulation Study
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