Histological and fine structural abnormalities in the livers of NZB/NZW F1 hybrid mice.

The livers of female NZB/NZW mice show several distinctive morphological abnormalities which become more pronounced as the animals age. These include focal necroses in the liver parenchyma, hyperplasia of Kupffer cells, the presence of plasma cells in hepatic sinusoids, and mononuclear cell infiltration around bile ducts in portal tracts. Fine structural changes include widespread dilatation of endoplasmic reticulum together with the presence of many cytolysosomes in hepatocytes. Such changes are not present in the livers of female Strong A mice of comparable age. The findings add another parameter to the definition of the natural history of NZB/NZW mice, and serve as a basis for further studies of the livers of these interesting animals.