Relationship of phosphatidylinositol bisphosphate hydrolysis to calcium mobilization and functional activation in fluoride-treated neutrophils.
Relationship of phosphatidylinositol bisphosphate hydrolysis to calcium mobilization and functional activation in fluoride-treated neutrophils.
复制标题
氟化物处理的中性粒细胞中磷脂酰肌醇二磷酸水解与钙动员和功能激活的关系。
DOI：
10.1172/jci113040
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Gabig,TG
中科院分区：
文献类型：
--
作者：
English,D;Debono,DJ;Gabig,TG
氟化钠（20mm）影响人中性粒细胞中磷脂酰肌醇二磷酸（PIP2）的快速水解。细胞内游离Ca2+水平在PIP2水解后但在呼吸爆发激活前升高。细胞内游离Ca2+水平的增加和功能激活的程度都取决于细胞外Ca2+的可用性。然而，当胞质内Ca2+的升高受到细胞外Ca2+消耗的严重限制时，F（-）刺激的PIP2水解速率不受影响。氟化物引起离体中性粒细胞质膜中PIP2的特异性水解。这种效果发生在低水平的可用Ca2+的存在，并伴随着肌醇磷酸盐的释放。我们得出结论，PIP2水解是中性粒细胞对F-反应的早期事件。这种反应不是Ca2+调节的，但可能导致Ca2+从细胞外介质流入。pip2特异性磷脂酶的激活不依赖于胞质游离Ca2+水平的变化，这可能是氟化物引发的刺激-反应途径的初始事件。
Sodium fluoride (20 mM) effected rapid hydrolysis of phosphatidylinositol bisphosphate (PIP2) in human neutrophils. Intracellular free Ca2+ levels increased after PIP2 hydrolysis but before respiratory burst activation. Both the increase in intracellular free Ca2+ levels and the extent of functional activation were dependent on the availability of extracellular Ca2+. The rate of F(-)-stimulated PIP2 hydrolysis, however, was not affected when the rise in cytosolic Ca2+ was severely limited by depletion of extracellular Ca2+. Fluoride caused the specific hydrolysis of PIP2 in isolated neutrophil plasma membranes. This effect occurred in the presence of low levels of available Ca2+ and was accompanied by the release of inositol phosphates. We conclude that PIP2 hydrolysis is an early event in the response of neutrophils to F-. This response is not Ca2+-regulated but may lead to an influx of Ca2+ from the extracellular medium. Activation of a PIP2-specific phospholipase independent of a change in cytosolic free Ca2+ levels may be the initial event in the stimulus-response pathway triggered by fluoride.