Fig. 3

Dynamics of Weibel-Palade body (WPB) formation in the cytoplasm of endothelial cells, as analysed by transmission electron microscopy. a General view of endothelial cell ultrastructure; scale bar 5 µm (left). Early stage of WPB formation from Golgi apparatus in the cells on the 2nd day after sorting (middle and right); scale bar 100 nm. b Immature WPBs with small quantities of folded vWF structures (left) and mature WPBs containing significant amounts of vWF (middle and right) detected on the 4th day after sorting; scale bar 100 nm. c The secretion of vWF-folded structures from mature WPBs to the extracellular space on the 8th day after sorting; scale bar 100 nm. WPBs are indicated by the arrowhead