Abstract
The responsiveness of the bone marrow cells to erythropoietin in vitro was investigated according to Krantz's method in order to clarify the abnormal mechanism of erythropoiesis in various blood diseases. The bone marrow cells of seven normal persons and twenty eight cases of the patients from hematological diseases were examined.
1) The heme synthesis rate of seven normal persons to erythropoietin was 331±77.8% of controls lacking erythropoietin.
2) Twelve cases of aplastic anemia showed the heme synthesis rate of 117±27.4% of controls. It was deduced, therefore, that the erythropoietin responsive cells (ERC) pool in aplastic anemia was decreased in comparison to normal controls.
3) The heme synthesis rate of four cases from pure red cell aplasia was 132±67.4% of controls. It was presumed that the quantitative decrease of the ERC pool or the qualitative defect of the ERC was present in the bone marrow cells from pure red cell aplasia.
4) The bone marrow cells of three cases from atypical leukemia showed the heme synthesis rate of 151±25.1%, which was less responsiveness to erythropoietin than normal controls but much more than aplastic anemia.
5) The heme synthesis rate of four cases from polycythemia vera was 339±109.8% of controls lacking erythropoietin. It was proved that some ERC which was responsive to EPO and could differentiate, existed in the bone marrow cells of the polycythemia vera.
