Localization of contractile-dependent Ca: comparison of Mn and verapamil in cardiac and skeletal muslce.
Localization of contractile-dependent Ca: comparison of Mn and verapamil in cardiac and skeletal muslce.
复制标题
收缩依赖性钙的定位：心肌和骨骼肌中锰和维拉帕米的比较。
DOI：
10.1152/ajplegacy.1975.229.4.1003
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发表时间：
1975
期刊：
影响因子：
--
通讯作者：
L. M. Nudd
中科院分区：
文献类型：
--
作者：
G. Langer;S. Serena;L. M. Nudd
两个兴奋-收缩解偶联剂，锰（Mn）和维拉帕米，在心脏和快速收缩骨骼肌的影响进行了比较。当在静止期期间施用药剂时，特别注意药剂对静止期之后的第一次收缩的影响。Mn显著降低心肌第一次搏动的dP/dt，而维拉帕米无显著影响。锰和维拉帕米对骨骼肌的第一次静止后收缩都没有显著影响，尽管维拉帕米在这两种组织的随后收缩中产生dP/dt的减小。在组织培养中的心脏细胞中的45 Ca交换的代理的效果的比较表明，锰诱导的快速置换的心脏细胞钙的快速交换的成分与随后的内流的增加。维拉帕米则相反，它不会产生快速的驱替，而只是产生一个持续的内流。这两种药物的功能和钙交换作用与模型相容，该模型将大部分收缩依赖性钙置于心肌细胞表面和快速收缩骨骼肌中更深的细胞内位点。
The effects of two excitation-contraction uncoupling agents, manganese (Mn) and verapamil, are compared in heart and fast-twitch skeletal muscle. Particular attention is given to the effect of the agents on the first contraction following a period of quiescence when the agents are administered during the quiescent period. Mn significantly diminishes dP/dt of the first beat in heart muscle, whereas verapamil has no significant effect. Neither Mn nor verapamil has a significant effect on the first postquiescent contraction in skeletal muscle, though verapamil produces a diminution of dP/dt in subsequent contractions in both tissues. A comparison of the effect of the agents on 45Ca exchange in heart cells in tissue culture indicates that Mn induces a rapid displacement of a rapidly exchangeable component of heart-cell calcium with subsequent inhibiton of influx. Verapamil, by contrast, produces no rapid displacement but only an inhibiton of influx. The functional and Ca-exchange effect of the two agents are compatible with a model which places most of the contractile-dependent Ca at the cellular surface in heart muscle and at deeper, intracellular sites in fast-twitch skeletal muscle.