ORIGIN OF THE CENTRAL CELLS OF ERYTHROBLASTIC ISLANDS IN FETAL MOUSE-LIVER - ULTRAHISTOCHEMICAL STUDIES OF MEMBRANE-BOUND GLYCOCONJUGATES

To clarify the origin of the central cells in hepatic erythroblastic i slands, glycoconjugates on the surface of cellular constituents in fet al mice liver were ultrahistochemically examined using lectin staining . At 11 days of gestation, the cells derived from mesenchyme in fetal liver, including sinusoidal macrophages, endothelial cells, and erythr opoietic cells, bound Griffonia simplicifolia isoagglutinin I-B4 (GS-I -B4), but hepatocytes lacked binding sites for the isolectln. Scavenge r macrophages in the hepatic cords at 13 days of gestation and the cen tral cells in the erythroblastic islands at 15 days of gestation also bound GS-I-B4. Hepatocytes, however, exhibited no GS-I-B4 binding site at any gestational day. At Il days of gestation, none of the cells in fetal liver had binding sites for soybean agglutinin (SEA), but cells derived from mesenchyme acquired these binding sites at 13 days of ge station. The central cells in the erythroblastic islands also bound SB A, but hepatocytes did not bind the lectin at all. The central cells i n the erythroblastic islands can be considered to belong to a mesenchy mal cell lineage, and primitive sinusoidal macrophages at II days of g estation are possible precursors of these central cells.