Immunohistochemical localization of vascular endothelial cell factor VIII/von Willebrand factor antigen in human...

Vascular endothelial cell factor VIII/von Willebrand factor antigen (FVIII/vWF Ag) of normal and disordered gastric tissues was studied with staphylococcus protein A-gold (PAG) labelling followed by photochemical silver reaction. FVIII/vWF Ag was localized clearly in the tissue fixed with various common fixatives and embedded in paraffin without enzyme treatment. The most satisfactory staining and the least nonspecific background were observed in the tissues fixed with Zamboni's and Bouin's solutions. The staining reaction could be enhanced, if the sections were pretreated with trypsin and subtilisin. Under the electron microscope, the gold particles were found over the Weibel-Palade bodies of vascular endothelial cells in the tissues fixed either in Zamboni's solution or in Zamboni's solution-osmium tetroxide, and embedded either with Lowicryl K4M or with Epon 812. It has been proved to be a better technique in investigation of FVIII/vWF Ag in vascular endothelial cells.