[Mouse hematopoietic organs in hypokinesia]

The capacity of hemopoietic cells for colony-formation and the pattern of their differentiation during hypokinesia were studied. The absolute count of colony-forming units (CFU) decreased exponentially during 3 to 30 days. Bone marrow showed a change in the total cell count and a wave-like change in the absolute and relative count of CFU with a maximum on the 1st-3rd and 15th-45th days. Differentiating potentialities of CFU from the spleen and bone marrow were not altered towards erythro-, myelo- and thrombopoiesis. The cell structure of the peripheral blood changed, displaying lymphopenia, transient neutrophil leukocytosis, increase in the percentage content of large lymphocytes and stress-lymphocytes.