[Hematopoietic stem cell count in mice with stimulated and suppressed erythropoiesis. II. Hypertransfusion of syngeneic erythrocytes and chronic hypoxia].

Polypotential hemopoietic stem cell numbers were monitored by means of the splenic colony-forming unit (CFU-S) method in bone marrow and spleen of CBA mice in condition of suppressed erythropoiesis (after syngeneic red blood cell hypertransfusion and chronic hypoxia). Erythropoietic activity determined by radioactive isotope 59Fe uptake in erythroid cells of spleen, bone marrow and erythrocytes of peripheral blood sharply decreased after these treatments. CFU-S contents in bone marrow and spleen increased during a week after syngeneic red blood cell hypertransfusion and after chronic hypoxia. It is assumed that the increase in hemopoietic stem cell contents in hemopoietic organs of mice under inhibited erythropoiesis may be interpreted due to the appearance of vacant differentiation potencies of stem cells, which in the normal state is realized in production of erythroid cells.