Calcium-induced calcium release from sarcoplasmic reticulum vesicles.
Calcium-induced calcium release from sarcoplasmic reticulum vesicles.
复制标题
钙诱导的钙从肌浆网囊泡中释放。
DOI：
10.1093/oxfordjournals.jbchem.a133529
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发表时间：
1981
影响因子：
2.7
通讯作者：
M. Kasai
中科院分区：
文献类型：
--
作者：
K. Nagasaki;M. Kasai
用45Ca微孔滤过法研究了肌浆网小泡对钙离子的被动通透性。当镁离子浓度较低时，钙离子外流速率随着微摩尔浓度的增加而增加。Ca~(2+)释放速率与囊外Ca~(2+)浓度的依赖关系不受囊内Ca~(2+)浓度的影响。咖啡因可促进钙离子释放，普鲁卡因和镁离子则抑制钙离子释放。这些特性表明，钙离子释放类似于在皮肤肌纤维中观察到的钙离子诱导的钙离子释放现象。外流曲线的动力学分析表明，我们的制剂中存在两种类型的囊泡；大约2/3的囊泡如上所述地释放钙离子，其余的不释放。
Passive permeability of sarcoplasmic reticulum vesicles for Ca2+ was studied by the Millipore filtration method using 45Ca. The efflux rate of Ca2+ increased in the presence of micromolar concentrations of Ca2+ in the medium when the Mg2+ concentration was low. The dependence of the Ca2+ release rate on the extravesicular Ca2+ concentration was not affected by the intravesicular Ca2+ concentration. The Ca2+ release was enhanced by caffeine, but reduced by procaine and Mg2+. These properties suggest that the Ca2+ release is a similar phenomenon to the Ca2+-induced Ca2+ release observed in skinned muscle fiber. Kinetic analysis of the efflux curves suggests that two types of vesicles exist in our preparation; about 2/3 of the vesicles release Ca2+ as described above and the remainder does not.