Scanning electron microscopy of human liver sinusoids.

Hepatic sinusoids of human liver samples obtained by surgical or needle biopsy were examined under the scanning and transmission electron microscopes (SEM and TEM). The surgically obtained tissues were perfused, by the use of a needle and syringe, with Ringer solution and successively with glutaraldehyde solution through the cut ends of blood vessels, while the needle biopsy pieces were perfused by directly puncturing the parenchyme. Endothelial cells of hepatic sinusoids possessed thin and flat cytoplasm with two types of fenestrations which have already been demonstrated in laboratory animals: smaller