Role of hemopoietic precursors of various classes in the effect of granulocyte colony-stimulating factor on hemopoiesis during cytostatic-induced myelosuppression.

Experiments were performed on the model of cyclophosphamide-induced myelosuppression. We showed that regeneration of the granulocytic hemopoietic stem is related to activation of multipotent, granulocyte-erythroid-macrophage-megakaryocyte, and granulocyte-macrophage precursors. The division and maturation of granulocyte colony-forming cells and significant decrease in the number of these cells in the bone were suppressed under these conditions. The granulocytopoiesis-stimulating effect of granulocyte CSF during myelosuppression was associated with an increase in functional activity of multipotent and granulocyte-erythroid-macrophage-megakaryocyte precursors (primarily of differentiation). In the period of regeneration, this effect was attributed to activity of granulocyte precursors.