EFFECTS OF COMBINATIONS OF STEM-CELL FACTOR AND HEMIN ON ERYTHROPOIESIS AFTER AZIDOTHYMIDINE TREATMENT OF IMMUNOSUPPRESSED MICE

Recombinant cytokines such as stem cell factor (SCF) are currently bei ng tested for the ability to ameliorate 3'azido-3'deoxythymidine (AZT) induced anemia in AIDS patients. Recently, we demonstrated that SCF a nd hemin in vitro greatly increased the resistance of burst-forming un its erythroid (BFU-E) to AZT. We therefore attempted to ameliorate AZT -induced anemia in vivo using SCF and hemin in immunodeficient LP-BM5 infected (MALDS) mice. SCF and hemin were administered with oral AZT f or 3 wk and the effects on erythropoiesis examined. Hemin significantl y increased hematocrits of AZT-treated mice and control mice. However, SCF and SCF-hemin combinations failed to raise hematocrits. Reticuloc yte numbers were significantly consistently increased only in hemin-tr eated mice receiving AZT. The numbers of CFU-E were increased in bone marrow of AZT-treated mice receiving hemin. Therefore, SCF did not enh ance the erythropoietic effect of hemin in AZT-treated immunodeficient mice.