A hitherto unrecognized bile ductular plexus in normal rat liver.

The three-dimensional arrangement of intrahepatic bile ducts was studied by scanning electron microscopy of biliary tract casts. Scanning electron microscopy of biliary casts revealed a complex of portal bile ductular channels. In the rabbit, it is focal and branching whereas in the rat, a plexus comprised of widespread and richly anastomosing network of tubules, 20 to 30 micron in diameter, is present. This plexus was prominent in the large portal tracts and was located at the border of the portal tracts and liver parenchyma. This biliary plexus may play a role in modifying original canalicular bile secreted by hepatocytes.