Movements of Calcium Ions and Their Role in the Activation of Platelets
Movements of Calcium Ions and Their Role in the Activation of Platelets
复制标题
钙离子的运动及其在血小板激活中的作用
DOI：
10.1055/s-0038-1648654
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发表时间：
1977
影响因子：
6.7
通讯作者：
E. Lüscher
中科院分区：
文献类型：
--
作者：
P. Massini;R. Käser;E. Lüscher
胞质钙浓度的升高在血小板活化的起始中起核心作用。在这一过程中，钙离子可能发生四种运动：(a)从膜中释放的钙离子诱导了膜的快速形状变化。(b)囊泡细胞器将钙离子释放到细胞质中，引发释放反应；(c)储存细胞器，称为致密体，在释放反应中向外分泌包括钙离子在内的内容物；(d)同时，质膜发生重排，导致其对钙离子的渗透性增加以及钙结合位点的数量增加。由于血小板活化过程中发生的大多数过程是可逆的，因此血小板必须配备一种从细胞质中去除钙离子的机制。血小板匀浆的泡状部分确实活跃地积累钙。这种钙泵受到环AMP和蛋白激酶的刺激；它可能参与血小板活化后的恢复。
The increase of the cytoplasmic Ca-concentration plays a central role in the initiation of platelet activation. Four kinds of movements of Ca-ions are presumed to occur during this process: (a) Ca-ions liberated from membranes induce the rapid shape change. (b) Vesicular organelles release Ca-ions into the cytoplasm which initiate the release reaction, (c) The storage organelles, called dense bodies, secrete their contents including Ca-ions to the outside during the release reaction, (d) At the same time a rearrangement of the plasma membrane occurs, resulting in an increase in its permeability for Ca-ions as well as in an increase in the number of Ca-binding sites. Since most processes occurring during platelet activation are reversible the platelet must be equipped with a mechanism which removes Ca-ions from the cytoplasm. A vesicular fraction of platelet homogenate indeed accumulates Ca actively. This Ca-pump is stimulated by cyclic AMP and protein kinase; it might be involved in the recovery of platelets after activation.