The excitation-contraction coupling mechanism in skeletal muscle.
The excitation-contraction coupling mechanism in skeletal muscle.
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DOI：
10.1007/s12551-013-0135-x
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发表时间：
2014-03-01
影响因子：
--
通讯作者：
Caputo, Carlo
中科院分区：
文献类型：
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作者：
Calderon, Juan C;Bolanos, Pura;Caputo, Carlo
兴奋-收缩耦合 (ECC) 一词首次由 Alexander Sandow 于 1952 年提出，描述了骨骼肌纤维质膜中发生的电事件与 SR 释放的 Ca2+ 之间的快速通信，从而导致收缩。抽搐骨骼肌的事件顺序涉及：(1) 动作电位沿着质膜启动和传播，(2) 电位在整个横管系统（T 管系统）中传播，(3) 二氢吡啶受体 (DHPR) 介导的膜电位变化检测，(4) DHPR 和肌浆网 (SR) 兰尼碱受体 (RyR) 之间的变构相互作用，(5) 释放来自 SR 的 Ca2+ 和肌质中 Ca2+ 浓度的短暂增加，(6) 肌质 Ca2+ 缓冲系统和收缩装置的激活，随后 (7) 主要通过 SR 通过 SR Ca2+ 三磷酸腺苷酶 (SERCA) 重新摄取 Ca2+ 介导的肌质 Ca2+ 消失，并在几种条件下移动到线粒体并被 Na+/Ca2+ 交换器 (NCX) 挤出。在本文中，我们回顾了骨骼肌 ECC 的基础知识以及用于研究它的技术。此外，我们强调了一些最新进展，并指出了与 ECC 相关的特定问题的知识差距，例如 (1) DHPR-RyR 分子相互作用，(2) 纤维类型的差异，(3) 肌肉疲劳期间的变化，(4) 线粒体和钙池操纵的 Ca2+ 进入在一般 ECC 序列中的作用，(5) 收缩增强剂，以及 (6) Ca2+ 火花。
First coined by Alexander Sandow in 1952, the term excitation-contraction coupling (ECC) describes the rapid communication between electrical events occurring in the plasma membrane of skeletal muscle fibres and Ca2+ release from the SR, which leads to contraction. The sequence of events in twitch skeletal muscle involves: (1) initiation and propagation of an action potential along the plasma membrane, (2) spread of the potential throughout the transverse tubule system (T-tubule system), (3) dihydropyridine receptors (DHPR)-mediated detection of changes in membrane potential, (4) allosteric interaction between DHPR and sarcoplasmic reticulum (SR) ryanodine receptors (RyR), (5) release of Ca2+ from the SR and transient increase of Ca2+ concentration in the myoplasm, (6) activation of the myoplasmic Ca2+ buffering system and the contractile apparatus, followed by (7) Ca2+ disappearance from the myoplasm mediated mainly by its reuptake by the SR through the SR Ca2+ adenosine triphosphatase (SERCA), and under several conditions movement to the mitochondria and extrusion by the Na+/Ca2+ exchanger (NCX). In this text, we review the basics of ECC in skeletal muscle and the techniques used to study it. Moreover, we highlight some recent advances and point out gaps in knowledge on particular issues related to ECC such as (1) DHPR-RyR molecular interaction, (2) differences regarding fibre types, (3) its alteration during muscle fatigue, (4) the role of mitochondria and store-operated Ca2+ entry in the general ECC sequence, (5) contractile potentiators, and (6) Ca2+ sparks.