Objective    To explore the functional expression and temporality of MDR1 gene in bone marrow of rabbits after autologous bone marrow transplantation with MDR1 transferred bone marrow mononuclear cells.     Methods    The supernatant of the amphotropic virus producer cell line PA317-HaMDR1/A was collected and concentrated to cocultivate with the bone marrow mononuclear cells of the rabbits. After large dose of chemotherapy with cyclophosphamide

the transferred cells were autotransplanted into the bone marrow. The integration

transfection rate and physiological function of MDR1 gene were tested by PCR

SP immunohistochemical method and daunorubicin (DNR) extrusion test respectively.      Results    After autologous bone marrow transplantation had been executed for 1-4 months

the integration of MDR1 gene in genome of bone marrow mononuclear cells was detected by PCR

and the expression rates of P-gp in cells tested by SP immunohistochemical method were 9.5％

8.5％

6.0% and 3.5％ respectively. The physiological function of MDR1 gene in bone marrow cells was proved by DNR extrusion test.     Conclusion    After the autotransplantation with bone marrow mononuclear cells transferred by MDR1 gene

the MDR1 gene can implant into the bone marrow of rabbits and has expressed functionally for 4 months

which has provided a basis for further research on chemoprotection experiment of the MDR1 gene transferred into the bone marrow cells.