ADIPOCYTE DEVELOPMENT AND THE LOSS OF ERYTHROPOIETIC CAPACITY IN THE BONE-MARROW OF MICE AFTER SUSTAINED HYPER-TRANSFUSION

  • 1 January 1982
    • journal article
    • research article
    • Vol. 60  (6) , 1337-1344
Abstract
In this EM study, erythropoiesis in mice was completely suppressed by repeated hypertransfusion for up to 6 wk. A sequence of ultrastructural changes in the marrow''s stromal cells that accompany the resulting shift from erythropoietic to granulopoietic tissue is described. These include the destruction of medullary macrophages, the accelerated development of marrow adipocytes and reticular cells, and a reduction in the amount of vascular space in the marrow. The absence of macrophages was highlighted by the complete lack of erythrophagocytosis in the marrows of hypertransfused mice injected with the hemolyzing agent, phenylhydrazine. The changes in the marrow stroma underlie the shift in the marrow''s hematopoietic microenvironment. Repeated phlebotomy of mice hypertransfused for 2 wk evoked the appearance of unique stromal cells in the marrow, similar to cells that are associated with accelerated erythropoiesis. The newly anemic mice were otherwise unable to mount an erythropoietic response to repeated bleeding, showing that the decline in the erythropoietic microenvironment brought on by sustained hypertransfusion was a lasting one.