The rate of tension recovery in cardiac muscle correlates with the relative residual tension prevailing after restretch.
The rate of tension recovery in cardiac muscle correlates with the relative residual tension prevailing after restretch.
复制标题
心肌张力恢复率与再拉伸后相对残余张力相关。
DOI：
10.1152/ajpheart.00714.2006
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Holbrook,AnastasiaM
中科院分区：
文献类型：
--
作者：
Campbell,KennethS;Holbrook,AnastasiaM
Isolated cardiac muscles generate tension more quickly at higher levels of Ca2+activation. We investigated the molecular mechanisms underlying this effect in permeabilized rat myocardial preparations by measuring the rate of tension recovery following brief shortening/restretch perturbations. Separate series of experiments used Ca2+-activating solutions with different pH values (pH 6.75, 7.00, and 7.25) and different phosphate (Pi) concentrations (0, 2.5, and 5.0 mM added Pi) to modulate the recovery kinetics. Subsequent analysis showed that the rate of tension recovery correlated (P< 0.001) with the relative residual tension, that is, the minimum tension measured immediately after restretch normalized to the steady-state isometric tension for the experimental condition. This new finding suggests that the rate at which cardiac muscles develop force increases with the proportion of cross bridges bound to the thin filament and is strong evidence of cooperative contractile activation.
