Key Laboratory of Biomedical Information Engineering of Education Ministry, Institute of Biomedical Analytical Technology and Instrumentation, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an 710049, China.
Comput Biol Med. 2011 Apr;41(4):206-10. doi: 10.1016/j.compbiomed.2011.02.001. Epub 2011 Feb 25.
Many experimental studies claimed that, short-term memory, an intrinsic property of paced cardiac myocytes, has been regulated by either intracellular calcium cycling or membrane ionic currents, manifested by a time constant of cellular action potential duration (APD) restitution. Although both factors play important roles in short-term memory, their respective effects have not been well understood currently. In this study, we used an ionic model of canine ventricular myocytes (CVM) to investigate the effect of calcium release from the sacroplasm reticulum (SR), as well as the effect of L-type calcium current, on cardiac short-term memory. We calculated short-term memory response by testing the time to reach steady-state APD after an abrupt shortening of basic cycling length (BCL) in pacing protocol. Our results indicated that as the release of calcium from SR was gradually prevented, short-term memory response decreased, while the blockade of L-type calcium channel had little effect on short-term memory. Finally, we declared that the amount of intracellular calcium released from SR affected short-term memory of cardiac tissues more than that of L-type calcium channel.
许多实验研究声称，作为心肌细胞固有特性的短期记忆，受到细胞内钙循环或膜离子电流的调节，表现为动作电位时程（APD）复极时间常数的改变。尽管这两个因素在短期记忆中都起着重要作用，但它们各自的作用目前还没有得到很好的理解。在这项研究中，我们使用犬心室肌细胞（CVM）的离子模型来研究肌浆网（SR）内钙释放以及 L 型钙电流对心脏短期记忆的影响。我们通过在起搏方案中突然缩短基本起搏周期长度（BCL）来测试达到稳定 APD 所需的时间，计算短期记忆反应。我们的结果表明，随着 SR 中钙释放的逐渐被阻止，短期记忆反应降低，而 L 型钙通道阻断对短期记忆几乎没有影响。最后，我们宣称，从 SR 释放的细胞内钙的量比 L 型钙通道对心脏组织的短期记忆影响更大。
