The mobilization of arachidonic acid in platelets exposed to thrombin or ionophore A23187. Effects of adenosine triphosphate deprivation.
The mobilization of arachidonic acid in platelets exposed to thrombin or ionophore A23187. Effects of adenosine triphosphate deprivation.
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暴露于凝血酶或离子载体 A23187 的血小板中花生四烯酸的动员。
DOI：
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发表时间：
1977
影响因子：
15.9
通讯作者：
D. Deykin
中科院分区：
文献类型：
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作者：
S. Rittenhouse;D. Deykin
在对人凝胶滤过的血小板进行的研究中，我们发现：(a)血清素的释放和[3H]花生四烯酸从磷脂酰胆碱和磷脂酰肌醇向浆磷脂酰乙醇胺的转移与凝血酶对血小板的激活有关，这两者都强烈依赖于代谢ATP的存在；(b)在无钙介质中，钙离子载体A-23187促进了标记磷脂中血清素的释放和花生四烯酸的动员；(c) ATP合成抑制剂虽然会导致离子载体诱导的释放反应受损，但不会抑制离子载体刺激的花生四烯酸的动员。我们得出结论，磷脂酶A2的激活，负责从血小板磷脂中释放花生四烯酸，完全依赖于离子载体或凝血酶以能量依赖的方式促进的细胞质钙离子水平的增加。磷脂酶的激活不是释放反应所提供的潜在水解活性的功能。
In studies conducted with human gel-filtered platelets, we have found: (a) that the release of serotonin and transfer of [3H]arachidonic acid from phosphatidylcholine and phosphatidylinositol to plasmalogen phosphatidylethanolamine which are associated with the activation of platelets by thrombin are both strongly dependent upon the presence of metabolic ATP; (b) that serotonin release and arachidonic acid mobilization in labeled phosphatides are promoted by the calcium ionophore A-23187 in media free of calcium ions; (c) that inhibitors of ATP synthesis, while leading to impairment of the release reaction induced by ionophore, do not inhibit ionophore-stimulated mobilization of arachidonic acid. We conclude that the activation of phospholipase A2 responsible for freeing arachidonic acid from platelet phosphatides is solely dependent upon the increased cytoplasmic levels of calcium ions promoted by either ionophore or, in an energy-dependent fashion by thrombin. Phospholipase activation is not a function of latent hydrolytic activity made available by the release reaction.