Cytoplasmic [Ca2+] in mammalian ventricle: dynamic control by cellular processes.
Cytoplasmic [Ca2+] in mammalian ventricle: dynamic control by cellular processes.
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哺乳动物心室中的细胞质 [Ca2]：细胞过程的动态控制。
DOI：
10.1146/annurev.ph.52.030190.002343
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发表时间：
1990
影响因子：
18.2
通讯作者：
W. Wier
中科院分区：
文献类型：
--
作者：
W. Wier
[Ca 2 +]i瞬变的定量重建是期望的目标，但该目标尚未达到。这将通过求解方程2来实现，一旦获得了其所有项的适当数学描述。如果计算的[Ca 2 +]i瞬变与许多实验条件下记录的瞬变非常匹配，那么我们可以确信我们对控制[Ca 2 +]i的细胞过程的理解是正确的。SL Ca ~（2+）ATP酶和SL Ca ~（2+）漏出对给定的搏动没有重要的贡献。所有可用的生理和生化数据清楚地表明，通过SL Ca 2（+）-ATP酶和SL Ca 2（+）-渗漏途径的Ca 2+通量与其他途径相比是很小的。然而，在许多搏动中，通过这些途径的流量将有助于SR的Ca 2+负载。在静息心肌的异常情况下，[Ca 2 +]i将由通过渗漏的Ca 2+内流与通过Na/Ca交换和SL Ca 2 + ATP酶的Ca 2+外流之间的平衡来确定。有一个新兴的共识，即在正常活动期间通过Na/Ca交换进入的Ca 2+的量很小。这一共识来自于对Na/Ca交换引起的[Ca 2 +]i变化的直接观察，来自于利用关于交换器的电流-电压关系和交换器电流与[Ca 2 +]i的定量关系的新定量数据的计算。显然，每次搏动时通过Na/Ca交换的Ca 2+流出是显著的。从理论和SL Ca 2+泵送很小的事实来看，通过交换器的Ca 2+流出量必须等于通过SL Ca 2+通道的Ca 2+流入量，但实验研究尚未定量验证这一点。所有研究，无论是最近的还是更早的，都表明所有哺乳动物物种中的[Ca 2 +]i瞬变都由SR释放的Ca 2+主导。即使在大鼠中，广泛认为是最依赖SR的物种，Ca 2+电流也贡献了可测量的Ca 2+（24）。只要SR不被静息耗尽，它是决定哺乳动物心室组织中给定搏动时[Ca 2 +]i瞬变的主要细胞实体。定量知识的流量的Ca 2+从它，需要评估理论的兴奋-收缩耦合，仍有待确定。
A quantitative reconstruction of [Ca2+]i transients is the desired goal, but that goal has yet to be reached. It will be reached by solving Equation 2., once an adequate mathematical description of all its terms is obtained. If computed [Ca2+]i transients match closely those recorded under many experimental conditions, then we can be confident that our understanding of the cellular processes that control [Ca2+]i is correct. The SL Ca2+ ATPase and the SL Ca2+ leak do not make an important contribution on a given beat. All the available data, physiologic and biochemical, indicate clearly that the Ca2+ fluxes via the SL Ca2(+)-ATPase and SL Ca2(+)-leak pathways are small in comparison to others. Over many beats, however, the fluxes through these pathways will contribute to loading of the SR with Ca2+. In the abnormal case of resting cardiac muscle, [Ca2+]i will be determined by the balance between Ca2+ influx via leak and Ca2+ efflux via Na/Ca exchange and SL Ca2+ ATPase. There is an emerging consensus that the amount of Ca2+ entering via Na/Ca exchange during normal activity is small. This consensus derives from direct observation of changes in [Ca2+]i attributable to Na/Ca exchange, from computations that utilize new quantitative data on the current-voltage relation of the exchanger and on the quantitative relationship of exchanger current to [Ca2+]i. Clearly, the efflux of Ca2+ via Na/Ca exchange on each beat is significant. From theory and the fact that SL Ca2+ pumping is small, the efflux of Ca2+ via the exchanger must equal the Ca2+ influx through SL Ca2+ channels, but experimental studies have not yet verified this quantitatively. All the studies, recent and older, indicate that the [Ca2+]i transient in all mammalian species is dominated by Ca2+ released from SR. Even in the rat, widely believed to be the species most dependent on SR, the Ca2+ current contributes measurable Ca2+ (24). Provided that the SR is not depleted by rest, it is the major cellular entity that determines the [Ca2+]i transient in mammalian ventricular tissue on a given beat. Quantitative knowledge of the flux of Ca2+ from it, required for evaluating theories of excitation-contraction coupling, still awaits determination.
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影响因子：
--
作者：
GUNTER, TE;RESTREPO, D;GUNTER, KK
通讯作者：
GUNTER, KK
通过电压依赖性过程松弛离体心室心肌细胞。
DOI：
10.1126/science.3406740
发表时间：
1988
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Bridge,JH;Spitzer,KW;Ershler,PR
通讯作者：
Ershler,PR
影响因子：
56.9
作者：
WIER, WG;CANNELL, MB;LEDERER, WJ
通讯作者：
LEDERER, WJ
影响因子：
5.5
作者：
ALLEN, DG;KURIHARA, S
通讯作者：
KURIHARA, S