The role of central adrenergic structures in the regulation of the erythroid hematopoietic stem was studied during administration of cyclophosphamide and 5-fluorouracil. The central nervous system contributed to suppression of erythropoiesis during cytostatic treatment. The suppressive effect of brain adrenergic structures on the erythron after treatment with cyclophosphamide and 5-fluorouracil was related to dysfunction of adherent cells in the hemopoiesis-inducing microenvironment (formation of hemopoietic islets and secretion of erythropoietic activity) and production of growth factors by myelokaryocytes, respectively. Brain norepinephrine had an inhibitory effect on proliferative activity and differentiation of erythroid precursors that were associated with the erythropoietin and peripheral alpha-adrenergic structures. However, stimulation of beta-adrenergic structures was followed by an increase in the rate of erythroid cell maturation.