Cytochemical and electron microscopic studies of rat liver with reduced capacity to transport conjugated bilirubin.

ALTHOUGH THE LIVERS OF RATS TREATED WITH AGENTS KNOWN TO SUPPRESS BILIRUBIN TRANSPORT APPEARED RELATIVELY NORMAL ON ROUTINE HISTOLOGICAL SECTIONS, CYTOCHEMICAL AND ELECTRON MICROSCOPIC PREPARATIONS REVEALED MARKED CHANGES IN: (a) levels of alkaline phosphatase and apparent ATPase activities of the cell membrane at the sinusoids, bile canaliculi, and between adjacent cells; (b) morphology of the bile canaliculi such as dilatation, fragmentation, vesiculation and reduced numbers of microvilli; (c) the number of lysosomes and their distribution within the cell. Similar changes in the cytochemistry of the liver cell were induced by extrahepatic obstruction.