We studied the effect of mesenchymal stem cells and hemopoietic stem cells co-transplanted in different regimens (sequence and intervals between the injections within 0-48 h) on the rate of the bone marrow hemopoiesis recovery in 468 inbred mice with cytostatic aplasia caused by a single injection of cyclophosphamide in a dose of 500 mg/kg. The efficacy of stem cells was evaluated by animal survival and general physical condition, body weight dynamics, peripheral blood counts (leucocytes, platelets, and reticulocytes), total cellularity and the presence of hemopoietic stem cells in the bone marrow on day 9 after cyclophosphamide injection. The relative content of hemopoietic stem cells in the total myelokaryocyte pool was assessed by flow cytofluorometry using specific monoclonal antibodies to CD117 and CD184. The stimulating effect of co-transplantation of mesenchymal stem cells and hemopoietic stem cells on hemopoiesis was demonstrated by the indices of total cellularity and the relative content of CD117+ hemopoietic stem cells. The schemes with injection of mesenchymal stem cells 24-48 h prior to injection of hemopoietic stem cells were most effective.
Keywords: co-transplantation; cyclophosphamide; hemopoietic stem cells; mesenchymal stem cells.