Scanning electron microscopy of mouse intrahepatic structures

Abstract

Livers of normal mice were prepared for scanning electron microscopic (SEM) study by fracturing or slicing lobes fixed in situ by perfusion with paraformaldehyde. Fracturing fixed liver exposes surfaces of hepatocytes and sinusoidal endothelial cells, whereas slicing the tissue reveals the internal structures of portal tracts. Earlier studies have delineated the major surface characteristics of hepatocytes and sinusoidal endothelial cells of rats. Surfaces of hepatocytes in the mouse differ from those in the rat by having larger and more numerous peg and hole complexes on the flat intercellular surface and less dense populations of perisinusoidal microvilli. Sinusoidal endothelial cells in the mouse have fewer large fenestrations than do similar cells in the rat; clusters of small fenestrations appear similarly distributed in both species. The surfaces of capsular mesothelial cells, Kupffer cells, bile duct epithelial cells, and endothelial cells of major vessels are similar in rat and mouse. The methods described for preparing liver for SEM examination are simple, rapid, and reproducible. The SEM is a useful tool with which to study intrahepatic surface structures, and its use may allow further correlations to be made between hepatic structure and function in both health and disease.