Zelechowska M G, van Mourik J A, Brodniewicz-Proba T
Nature. 1985;317(6039):729-30. doi: 10.1038/317729a0.
Factor VIII is generally believed to circulate in blood as a multimeric complex of two glycoproteins which are physiologically and immunologically distinct. One component of the factor VIII complex is factor VIII procoagulant activity (FVIII:C) which is associated with factor VIII/procoagulant antigen (FVIII:Ag, formerly FVIII/CAg). The second, larger unit of the complex is factor VIII/von Willebrand factor (vWF:Ag, formerly factor VIII-related antigen or FVIIIRAg). FVIII:C has anti-haemophilic activity and is defective or deficient in patients with classical haemophilia, and vWF:Ag is absent in patients with von Willebrand disease. FVIII:Ag was demonstrated recently in endothelial cells lining hepatic sinusoids, by using immunoperoxidase staining and light microscopy, whereas biochemical data had indicated its presence predominantly in the hepatocyte fractions and in lesser amounts in endothelial cells. Moreover, recent hybridization experiments detected FVIII:C messenger RNA in liver and kidney tissues. Despite several efforts, the cells responsible for FVIII:C synthesis have not been unequivocally identified. Here we use protein A-gold complex labelling to demonstrate the ultrastructural localization of FVIII:C in human liver cells; the results indicate that hepatocytes may synthesize FVIII:Ag.
一般认为，凝血因子VIII在血液中以两种糖蛋白的多聚体复合物形式循环，这两种糖蛋白在生理和免疫方面都有所不同。凝血因子VIII复合物的一个成分是凝血因子VIII促凝活性（FVIII:C），它与凝血因子VIII/促凝抗原（FVIII:Ag，以前称为FVIII/CAg）相关。复合物的第二个更大的单位是凝血因子VIII/血管性血友病因子（vWF:Ag，以前称为凝血因子VIII相关抗原或FVIIIRAg）。FVIII:C具有抗血友病活性，在典型血友病患者中存在缺陷或缺乏，而vWF:Ag在血管性血友病患者中不存在。最近，通过免疫过氧化物酶染色和光学显微镜检查，在肝窦内衬的内皮细胞中发现了FVIII:Ag，而生化数据表明其主要存在于肝细胞部分，在内皮细胞中的含量较少。此外，最近的杂交实验在肝脏和肾脏组织中检测到了FVIII:C信使核糖核酸。尽管进行了多项努力，但负责FVIII:C合成的细胞尚未得到明确鉴定。在这里，我们使用蛋白A-金复合物标记来证明FVIII:C在人肝细胞中的超微结构定位；结果表明肝细胞可能合成FVIII:Ag。
