The control of sarcoplasmic reticulum Ca content in cardiac muscle
The control of sarcoplasmic reticulum Ca content in cardiac muscle
复制标题
DOI：
10.1016/j.ceca.2005.06.017
复制
发表时间：
2005-09-01
期刊：
影响因子：
4
通讯作者：
Eisner, DA
中科院分区：
文献类型：
--
作者：
Díaz, ME;Graham, HK;Eisner, DA
大多数激活心脏收缩的钙来自肌浆网（SR），因此控制SR钙含量是至关重要的。SR Ca含量反映了摄取（通过SR Ca- atp酶，SERCA）和释放（主要通过ryanodine受体（RyR））之间的平衡。可以防止不必要的SR Ca变化，因为，例如，SR Ca含量的增加增加了收缩期Ca瞬态的振幅，这反过来又导致Ca从细胞中损失增加并减少Ca进入细胞，从而使细胞和SR Ca恢复到控制水平。我们讨论了影响SR - Ca稳定水平的参数，以及这些参数在心力衰竭时可能发生的变化。最后，我们讨论紊乱的钙调节，特别强调交替的条件下，连续的心跳在振幅交替。这种行为可以用控制SR Ca的过程中过多的反馈增益来解释。(C) 2005 Elsevier Ltd。版权所有。
Most of the calcium that activates contraction in the heart comes from the sarcoplasmic reticulum (SR) and it is therefore essential to control the SR Ca content. SR Ca content reflects the balance between uptake (via the SR Ca-ATPase, SERCA) and release, largely via the ryanodine receptor (RyR). Unwanted changes of SR Ca are prevented because, for example, an increase of SR Ca content increases the amplitude of the systolic Ca transient and this, in turn, results in increased loss of Ca from and decreased Ca entry into the cell thereby restoring cell and SR Ca towards control levels. We discuss the parameters that affect the steady level of SR Ca and how these may change in heart failure. Finally, we discuss disordered Ca regulation with particular emphasis on the condition of alternans where successive heartbeats alternate in amplitude. This behaviour can be explained by excessive feedback gain in the processes controlling SR Ca. (C) 2005 Elsevier Ltd. All rights reserved.