Numerical Analysis of the Effect of T-tubule Location on Calcium Transient in Ventricular Myocytes
Numerical Analysis of the Effect of T-tubule Location on Calcium Transient in Ventricular Myocytes
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DOI：
10.3233/bme-130932
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发表时间：
2014-01-01
影响因子：
1
通讯作者：
Yu, Zeyun
中科院分区：
文献类型：
--
作者：
George, Uduak Z.;Wang, Jun;Yu, Zeyun
心肌细胞内钙（Ca 2+）信号传导对心脏的正常功能至关重要。了解细胞内Ca 2+动力学将有助于了解正常和患病心脏的功能。在目前的研究中，时空Ca 2+动力学研究心室肌细胞考虑Ca 2+的释放和再摄取通过肌膜和横小管（T-小管），Ca 2+的扩散和缓冲在胞质溶胶中，和与肌浆网相关的Ca 2+的活动的封锁。本研究使用从部分心室肌细胞的电子显微镜（EM）图像中提取的T-小管的分支的三维（3D）几何模型进行。通过使用涉及Ca 2+、缓冲液和膜通道的偏微分方程系统进行数学建模。数值模拟结果表明，在细胞表面附近的T-小管结构的缺乏，可以增加在心肌细胞中的Ca 2+浓度的峰值时间。结果还表明，T-小管和移动的缓冲液在心室肌细胞钙瞬变的调节中起重要作用。
Intracellular calcium (Ca2+) signaling in cardiac myocytes is vital for proper functioning of the heart. Understanding the intracellular Ca2+ dynamics would give an insight into the functions of normal and diseased hearts. In the current study, spatiotemporal Ca2+ dynamics is investigated in ventricular myocytes by considering Ca2+ release and re-uptake via sarcolemma and transverse tubules (T-tubules), Ca2+ diffusion and buffering in the cytosol, and the blockade of Ca2+ activities associated with the sarcoplasmic reticulum. This study is carried out using a three dimensional (3D) geometric model of a branch of T-tubule extracted from the electron microscopy (EM) images of a partial ventricular myocyte. Mathematical modeling is done by using a system of partial differential equations involving Ca2+, buffers, and membrane channels. Numerical simulation results suggest that a lack of T-tubule structure at the vicinity of the cell surface could increase the peak time of Ca2+ concentration in myocytes. The results also show that T-tubules and mobile buffers play an important role in the regulation of Ca2+ transient in ventricular myocytes.