[Effect of bone marrow cells on the clonal growth of granulocyte-macrophage precursors in a soft agar].

The granulocyte-macrophage colony stimulating effect of bone marrow cells is shown to be less intensive than the stimulating effect of feeding leukocytes. It is supposed that these two stimulating substances activate different progenitor populations. Stimulating effect of mixture consisting of leukocytes and bone marrow cells are very close to that of bone marrow cells alone. Leukemic bone marrow cells demonstrate the least colony stimulating ability.