Eichholtz T, Jalink K, Fahrenfort I, Moolenaar W H
Division of Cellular Biochemistry, The Netherlands Cancer Institute, Amsterdam.
Biochem J. 1993 May 1;291 ( Pt 3)(Pt 3):677-80. doi: 10.1042/bj2910677.
Lysophosphatidic acid (LPA) is a water-soluble phospholipid with hormone-like and growth-factor-like activities. LPA activates a putative G-protein-coupled receptor in responsive cells, but the natural source of exogenous LPA is unknown. Here we show that LPA is present in mammalian serum in an active form (bound to albumin) at concentrations of 1-5 microM, but is not detectable in platelet-poor plasma, suggesting that LPA is produced during blood clotting. We find that thrombin activation of platelets prelabelled with [32P]Pi results in the rapid release of newly formed [32P]LPA into the extracellular environment. We conclude that LPA is a novel platelet-derived lipid mediator that may play a role in inflammatory and proliferative responses to injury.
溶血磷脂酸（LPA）是一种具有激素样和生长因子样活性的水溶性磷脂。LPA可激活反应性细胞中一种假定的G蛋白偶联受体，但外源性LPA的天然来源尚不清楚。我们在此表明，LPA以活性形式（与白蛋白结合）存在于哺乳动物血清中，浓度为1 - 5微摩尔，但在血小板缺乏的血浆中无法检测到，这表明LPA是在血液凝固过程中产生的。我们发现，用[32P]Pi预标记的血小板经凝血酶激活后，会迅速将新形成的[32P]LPA释放到细胞外环境中。我们得出结论，LPA是一种新型的血小板衍生脂质介质，可能在对损伤的炎症和增殖反应中起作用。
