Wencel-Drake J D, Plow E F, Zimmerman T S, Painter R G, Ginsberg M H
Am J Pathol. 1984 May;115(2):156-64.
The distribution and transport of thrombospondin (TSP), fibrinogen (Fbg), fibronectin (Fn), and Factor VIII-related antigen (VIII:RAg) in resting and thrombin-stimulated platelets was investigated by immunofluorescence microscopy. In resting intact cells, little surface staining was seen for these proteins. In permeable resting cells, punctate staining similar to that reported for platelet factor 4 was observed. Double-label immunofluorescence staining for Fbg and either beta-thromboglobulin (beta TG), TSP, or Fn demonstrated co-localization, indicating their presence in the same intracellular structures. VIII:RAg showed general co-localization; however, the staining was finer, suggesting a possible differential intragranular localization. Thrombin stimulation induced the appearance of larger (approximately 0.5 mu) immunofluorescent masses of these proteins. In thrombin-stimulated cells, co-localization of all proteins in these masses was observed by double label immunofluorescence. Thus, TSP, Fbg, Fn, and beta TG are localized in the same structure in resting cells. Thrombin stimulates formation of common larger masses of these proteins prior to their release, suggesting that they reach the cell surface through a common intermediate.
通过免疫荧光显微镜研究了血小板反应蛋白（TSP）、纤维蛋白原（Fbg）、纤连蛋白（Fn）和因子VIII相关抗原（VIII:RAg）在静息和凝血酶刺激的血小板中的分布和转运。在静息的完整细胞中，这些蛋白质几乎没有表面染色。在可渗透的静息细胞中，观察到类似于血小板因子4报道的点状染色。对Fbg与β-血小板球蛋白（βTG）、TSP或Fn进行双标记免疫荧光染色显示共定位，表明它们存在于相同的细胞内结构中。VIII:RAg显示出普遍的共定位；然而，染色更精细，提示可能存在颗粒内定位差异。凝血酶刺激导致这些蛋白质出现更大（约0.5μm）的免疫荧光团块。在凝血酶刺激的细胞中，通过双标记免疫荧光观察到所有蛋白质在这些团块中共定位。因此，TSP、Fbg、Fn和βTG在静息细胞中定位于相同结构。凝血酶在这些蛋白质释放之前刺激形成共同的更大团块，表明它们通过共同的中间体到达细胞表面。
