FIGURE 13 Top, left: secretory vesicles just beneath the sinusoidal border in an experimental section
contain highly reacted VLDL particles (perfused with 1% formaldehyde). Similar particles are seen among
the microvilli at the space of Disse (arrow). Note the increased electron density of the plasma membrane of
the microvilli (arrowhead). Stained with lead citrate, x 30,000. Top, right: the secretory vesicle at the top of
the field has fused with the plasma membrane, releasing reacted VLDL particles into the space of Disse.
Note the increased electron density of its membrane as well as the membrane of the vesicle just below it
(arrows). Liver perfused with 1% formaldehyde. No lead stain. • 30,000. Bottom: highly reacted VLDL
particles among the microvilli of the triangular space of Disse between hepatocytes. The arrows indicate
particles on which the reaction product is much denser at the periphery, indicating that the reaction takes
place at the surface of the particle. Note the increased electron density of the microvillous plasma
membrane (double arrows). Liver perfused with 4% formaldehyde and stained with lead citrate. • 32,000.