Disorder in Excitation‐Contraction Coupling of Cardiac Muscle from Cats with Experimentally Produced Right Ventricular Hypertrophy
Disorder in Excitation‐Contraction Coupling of Cardiac Muscle from Cats with Experimentally Produced Right Ventricular Hypertrophy
复制标题
实验性右心室肥大猫心肌兴奋收缩耦合紊乱
DOI：
10.1161/01.res.28.3.346
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发表时间：
1971
影响因子：
20.1
通讯作者：
H. Wirth
中科院分区：
文献类型：
--
作者：
R. Kaufmann;H. Homburger;H. Wirth
The contractile and electrical activity of papillary muscles from hypertrophied right ventricles of cats with artificial stenosis of the pulmonary artery was investigated. Contractility was considerably decreased along the entire force-velocity relationship, whereas no measurable alterations could be detected in the electrical activities as recorded by intracellular microelectrodes. By supramaximal Ca2+ activation, the contractility of both the hypertrophied and the normal control preparations was increased to about the same final value. These findings are consistent with the concept that a disorder in the mechanism of excitation-contraction coupling underlies the depressed contractile state of hypertrophied cardiac muscle. In addition, it could be shown that the increase in volume of each cellular unit is clearly related to the decrease in contractility. This can tentatively be explained by the following assumptions. If the amount of Ca2+ entering the cell per unit area is not changed in hypertrophy, then in a cell of increased diameter, the amount of Ca2+ distributed per unit cell volume will be diminished. Since the excitation-contraction coupling of the heart is very sensitive to Ca2+, this Ca2+ deficit should be reflected in a depression of contractility.
