Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, UK (G.L.S.).
Unit of Cardiac Physiology, Division of Cardiovascular Sciences, University of Manchester, UK (D.A.E.).
Circulation. 2019 May 14;139(20):2358-2371. doi: 10.1161/CIRCULATIONAHA.118.039329.
Changes of intracellular Ca concentration regulate many aspects of cardiac myocyte function. About 99% of the cytoplasmic calcium in cardiac myocytes is bound to buffers, and their properties will therefore have a major influence on Ca signaling. This article considers the fundamental properties and identities of the buffers and how to measure them. It reviews the effects of buffering on the systolic Ca transient and how this may change physiologically, and in heart failure and both atrial and ventricular arrhythmias, as well. It is concluded that the consequences of this strong buffering may be more significant than currently appreciated, and a fuller understanding is needed for proper understanding of cardiac calcium cycling and contractility.
细胞内钙离子浓度的变化调节着心肌细胞功能的多个方面。心肌细胞中约 99%的细胞质钙与缓冲剂结合，因此其特性将对 Ca 信号转导产生重大影响。本文考虑了缓冲剂的基本特性和身份，以及如何测量它们。它回顾了缓冲作用对收缩期 Ca 瞬变的影响，以及这种影响在生理、心力衰竭以及房性和室性心律失常中是如何变化的。结论是，这种强烈缓冲的后果可能比目前人们所认识到的更为重要，为了正确理解心脏钙循环和收缩性，需要有更全面的认识。
