Maloney J P, Silliman C C, Ambruso D R, Wang J, Tuder R M, Voelkel N F
Department of Pulmonary Sciences, University of Colorado School of Medicine and the Bonfils Blood Center, Denver, Colorado 80262, USA.
Am J Physiol. 1998 Sep;275(3):H1054-61. doi: 10.1152/ajpheart.1998.275.3.H1054.
Platelet aggregation is a cardinal feature of both vascular repair and vascular disease. During aggregation platelets release a variety of vasoactive substances; some of these promote angiogenesis, endothelial permeability, and endothelial growth, actions shared by vascular endothelial growth factor (VEGF). This study was undertaken to investigate the hypothesis that VEGF is released by aggregating platelets. We found that VEGF was secreted during the in vitro aggregation of platelet-rich plasma induced by thrombin, collagen, epinephrine, and ADP (range 23-518 pg VEGF/ml). Furthermore, serum VEGF levels were elevated compared with plasma (230 +/- 63 vs. 38 +/- 8 pg VEGF/ml), indicative of VEGF release during whole blood coagulation. Lysates of apheresed, leukocyte-poor platelet units contained significant amounts of VEGF (2.4 +/- 0.8 pg VEGF/mg protein). VEGF message and protein were also present in a megakaryocytic cell line (Dami cell). These results suggest constitutive roles for platelet VEGF in the repair of intimal vessel injury and in the altered permeability and intimal proliferation seen at sites of platelet aggregation and thrombosis.
血小板聚集是血管修复和血管疾病的主要特征。在聚集过程中，血小板释放多种血管活性物质；其中一些物质可促进血管生成、内皮通透性和内皮生长，这些作用与血管内皮生长因子（VEGF）相同。本研究旨在探讨聚集的血小板释放VEGF这一假说。我们发现，在凝血酶、胶原、肾上腺素和ADP诱导的富含血小板血浆体外聚集过程中会分泌VEGF（范围为23 - 518 pg VEGF/ml）。此外，与血浆相比，血清VEGF水平升高（230±63 vs. 38±8 pg VEGF/ml），表明在全血凝固过程中会释放VEGF。去除白细胞的单采血小板单位的裂解物含有大量VEGF（2.4±0.8 pg VEGF/mg蛋白）。VEGF信息和蛋白也存在于巨核细胞系（Dami细胞）中。这些结果表明血小板VEGF在内膜血管损伤修复以及在血小板聚集和血栓形成部位出现的通透性改变和内膜增殖中起组成性作用。
