Massini P, Lüscher E F
Biochim Biophys Acta. 1976 Jul 1;436(3):652-63. doi: 10.1016/0005-2736(76)90447-8.
Blood platelets, upon stimulation with various substances, take up calcium ions from the suspending medium. This influx occurs simultaneously with the release reaction, i.e. the specific secretion of a variety of substances from storage organelles and the second wave of aggregation. Various inhibitors of the release reaction inhibit this Ca2+ influx. Platelets previously loaded with 45Ca show an increased efflux of the cation upon stimulation by thrombin. These results suggest that the plasma membrane acquires an increased permeability to Ca2+ only in a later phase of platelet activation, in most cases after the earlier release of Ca2+ into the cytoplasm from Castoring organelles. Rapid shape change and release proceed independently of external calcium, whereas clot retraction depends upon a prolonged increased permeability of the plasma membrane to this cation.
血小板在受到各种物质刺激后，会从悬浮介质中摄取钙离子。这种内流与释放反应同时发生，即从储存细胞器中特异性分泌多种物质以及第二波聚集反应。释放反应的各种抑制剂会抑制这种钙离子内流。预先加载了45Ca的血小板在凝血酶刺激后会出现阳离子外流增加。这些结果表明，质膜仅在血小板激活的后期才对钙离子具有增加的通透性，在大多数情况下是在钙离子从储存细胞器早期释放到细胞质之后。快速的形状变化和释放独立于细胞外钙进行，而血块回缩则取决于质膜对这种阳离子的通透性长时间增加。
