SUPPRESSIVE EFFECTS OF AN EXTRA-MEDULLARY TUMOR ON BONE-MARROW ERYTHROPOIESIS AND STROMA

  • 1 January 1978
    • journal article
    • research article
    • Vol. 6  (6) , 568-575
Abstract
Mice bearing a solid extramedullary Ehrlich ascites tumor developed anemia, reticulocytosis and leukocytosis after 3 wk of tumor growth. Erythopoiesis in the marrow as measured by erythroblast counts and radioiron uptake of the humerus and femur was suppressed to less than 30% of normal. Striking erythroblastic and granulocytic hyperplasia in the spleen occurred to compensate for suppression of erythropoiesis in the marrow. Accompanying the medullary erythropoietic insufficiency was a similar suppression to 30% of normal in the growth of bone marrow stromal colonies in vitro. Because erythropoiesis was suppressed in the marrow but not in the spleen and bone marrow stromal colony growth was concomitantly suppressed, a change in the cellular component of the hemopoietic microenvironment is suggested. Splenectomy prior to tumor inoculation did not ameliorate the anemia. Removing this potentially compensatory site for erythropoiesis prevented the severe suppression of erythroblast counts and stromal colony growth from the marrow. With sufficient stimulus the suppression of erythropoiesis in the marrow apparently was preventable.