Noll Laboratory and Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Adv Physiol Educ. 2011 Mar;35(1):22-7. doi: 10.1152/advan.00119.2010.
The primary purpose of this article is to present a basic overview of some key teaching concepts that should be considered for inclusion in an six- to eight-lecture introductory block on the regulation of cardiac performance for graduate students. Within the context of cardiac excitation-contraction coupling, this review incorporates information on Ca(2+) microdomains and local control theory, with particular emphasis on the role of Ca(2+) sparks as a key regulatory component of ventricular myocyte contraction dynamics. Recent information pertaining to local Ca(2+) cycling in sinoatrial nodal cells (SANCs) as a mechanism underlying cardiac automaticity is also presented as part of the recently described coupled-clock pacemaker system. The details of this regulation are emerging; however, the notion that the sequestration and release of Ca(2+) from internal stores in SANCs (similar to that observed in ventricular myocytes) regulates the rhythmic excitation of the heart (i.e., membrane ion channels) is an important advancement in this area. The regulatory role of cardiac adrenergic receptors on cardiac rate and function is also included, and fundamental concepts related to intracellular signaling are discussed. An important point of emphasis is that whole organ cardiac dynamics can be traced back to cellular events regulating intracellular Ca(2+) homeostasis and, as such, provides an important conceptual framework from which students can begin to think about whole organ physiology in health and disease. Greater synchrony of Ca(2+)-regulatory mechanisms between ventricular and pacemaker cells should enhance student comprehension of complex regulatory phenomenon in cardiac muscle.
本文的主要目的是介绍一些关键教学概念的基本概述，这些概念应包含在针对研究生的六到八次讲座的心脏功能调节入门课程中。在心脏兴奋-收缩偶联的背景下，本综述纳入了关于 Ca(2+)微区和局部控制理论的信息，特别强调 Ca(2+)火花作为心室肌收缩动力学关键调节成分的作用。最近有关窦房结细胞（SANC）局部 Ca(2+)循环作为心脏自律性机制的信息也作为最近描述的偶联时钟起搏系统的一部分呈现。这些调节的细节正在出现；然而，认为 SANC 中内部储存的 Ca(2+)的隔离和释放（类似于在心室肌细胞中观察到的）调节心脏的节律性兴奋（即膜离子通道）的观点是该领域的一个重要进展。心脏肾上腺素能受体对心脏率和功能的调节作用也包括在内，并讨论了与细胞内信号转导相关的基本概念。一个重要的强调重点是，整个器官的心脏动力学可以追溯到调节细胞内 Ca(2+)稳态的细胞事件，因此，为学生提供了一个重要的概念框架，使他们能够开始思考健康和疾病状态下的整个器官生理学。心室和起搏细胞之间 Ca(2+)调节机制的更大同步性应增强学生对心脏肌肉中复杂调节现象的理解。
