Data from: Effects of rogue ryanodine receptors on Ca2+ sparks in cardiac myocytes

Ca2+ sparks and Ca2+ quarks, arising from clustered and rogue ryanodine receptors (RyRs), are significant Ca2+ release events from the junctional sarcoplasmic reticulum (JSR). Based on the anomalous subdiffusion of Ca2+ in the cytoplasm, a mathematical model was developed to investigate the effects of rogue RyRs on Ca2+ sparks in cardiac myocytes. Ca2+ quarks and sparks from the stochastic opening of rogue and clustered RyRs are numerically reproduced and agree with experimental measurements. It is found that the stochastic opening Ca2+ release units (CRUs) of clustered RyRs are regulated by free Ca2+ concentration in the JSR lumen (i.e. [Ca2+]lumen). The frequency of spontaneous Ca2+ sparks is remarkably increased by the rogue RyRs opening at high [Ca2+]lumen, but not at low [Ca2+]lumen. Hence, the opening of rogue RyRs contributes to the formation of Ca2+ sparks at high [Ca2+]lumen. The interplay of Ca2+ sparks and Ca2+ quarks has been discussed in detail. This work is of significance to provide insight into understanding Ca2+ release mechanisms in cardiac myocytes

Data_Sheet_1_The Interplay of Rogue and Clustered Ryanodine Receptors Regulates Ca2+ Waves in Cardiac Myocytes.docx

<p>Ca²⁺ waves in cardiac myocytes can lead to arrhythmias owing to delayed after-depolarisations. Based on Ca²⁺ regulation from the junctional sarcoplasmic reticulum (JSR), a mathematical model was developed to investigate the interplay of clustered and rogue RyRs on Ca²⁺ waves. The model successfully reproduces Ca²⁺ waves in cardiac myocytes, which are in agreement with experimental results. A new wave propagation mode of “spark-diffusion-quark-spark” is put forward. It is found that rogue RyRs greatly increase the initiation of Ca²⁺ sparks, further contribute to the formation and propagation of Ca²⁺ waves when the free Ca²⁺ concentration in JSR lumen ([Ca²⁺]_lumen) is higher than a threshold value of 0.7 mM. Computational results show an exponential increase in the velocity of Ca²⁺ waves with [Ca²⁺]_lumen. In addition, more CRUs of rogue RyRs and Ca²⁺ release from rogue RyRs result in higher velocity and amplitude of Ca²⁺ waves. Distance between CRUs significantly affects the velocity of Ca²⁺ waves, but not the amplitude. This work could improve understanding the mechanism of Ca²⁺ waves in cardiac myocytes.</p

The Interplay of Rogue and Clustered Ryanodine Receptors Regulates Ca2+ Waves in Cardiac Myocytes

Ca2+ waves in cardiac myocytes can lead to arrhythmias owing to delayed after-depolarisations. Based on Ca2+ regulation from the junctional sarcoplasmic reticulum (JSR), a mathematical model was developed to investigate the interplay of clustered and rogue RyRs on Ca2+ waves. The model successfully reproduces Ca2+ waves in cardiac myocytes, which are in agreement with experimental results. A new wave propagation mode of “spark-diffusion-quark-spark” is put forward. It is found that rogue RyRs greatly increase the initiation of Ca2+ sparks, further contribute to the formation and propagation of Ca2+ waves when the free Ca2+ concentration in JSR lumen ([Ca2+]lumen) is higher than a threshold value of 0.7 mM. Computational results show an exponential increase in the velocity of Ca2+ waves with [Ca2+]lumen. In addition, more CRUs of rogue RyRs and Ca2+ release from rogue RyRs result in higher velocity and amplitude of Ca2+ waves. Distance between CRUs significantly affects the velocity of Ca2+ waves, but not the amplitude. This work could improve understanding the mechanism of Ca2+ waves in cardiac myocytes

Interplay of Proximal Flow Confluence and Distal Flow Divergence in Patient-Specific Vertebrobasilar System - Fig 7

<p>(A-F) TAWSS and (G-L) OSI near vertebrobasilar flow divergence with BA bifurcating into LSCA, RSCA, LPCA and RPCA.</p

Demographics of the study population.

<p>Demographics of the study population.</p

Bifurcation Asymmetry of Small Coronary Arteries in Juvenile and Adult Mice

Background: Microvascular bifurcation asymmetry is of significance for regulation of coronary flow heterogeneity during juvenile and adult growth. The aim of the study is to investigate the morphometric and hemodynamic variation of coronary arterial bifurcations in mice of different ages.Methods: Pulsatile blood flows were computed from a Womersley-type model in the reconstructed left coronary arterial (LCA) trees from Micro-CT images in normal mice at ages of 3 weeks, 6 weeks, 12 weeks, 5-6 months, and &gt;8 months. Diameter and flow ratios and bifurcation angles were determined in each bifurcation of the LCA trees.Results: The blood volume and inlet flow rate of LCA trees increase and decrease during juvenile and adult growth, respectively. As vessel diameters decrease, the increased ratios of small to large daughter vessel diameters (Ds/Dl) result in more uniform flows and lower velocities. There are significant structure-functional changes of LCA trees in mice of &gt;8 months compared with mice of &lt; 8 months. As Ds/Dl increases, the variation trend of bifurcation angle during juvenile growth is different from that during adult growth.Conclusions: Although inlet flows are different in adult vs. juvenile mice, the adult still have uniform flow and low velocity. This is accomplished through a decrease in diameter. The design ensures ordered dispersion of red cells through asymmetric branching patterns into the capillaries

Statistics for junctional surface area, SAR-TAWSS, and SAR-OSI at vertebrobasilar flow convergence and divergence.

<p>Statistics for junctional surface area, SAR-TAWSS, and SAR-OSI at vertebrobasilar flow convergence and divergence.</p