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 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.