This study demonstrates that extramedullary hematopoiesis occurs in livers of 
adult lpr mice and, after treatment with each of three xenobiotic 
compounds--phenobarbital, cyproterone acetate, and nafenopin--it includes 
granulopoiesis. lpr mice are used as a model of the human disease systemic lupus 
erythematosus (SLE). The develop a syndrome very similar to that of human 
sufferers. In untreated lpr mice, mononuclear white blood cells were discernible 
in hepatic sinusoidal foci; T and B lymphocytes were distinguished from each 
other by immunocytochemistry at light microscope level. After treatment with any 
of the xenobiotic compounds, immunolabeling demonstrated the additional presence 
of granulocytes in foci, and, at electron microscope level neutrophils, 
eosinophils and their precursors were clearly recognizable.