Hepatic extramedullary granulopoiesis after treatment with liver-stimulatory xenobiotics, in lpr mice

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