Granulocyte colony-stimulating factor and drugs elevating extracellular adenosine act additively to enhance the hemopoietic spleen colony formation in irradiated mice

The effects of combined administration of two drugs elevating extracellular adenosine, namely dipyridamole (DP) and adenosine monophosphate (AMP), and granulocyte colony-stimulating factor (G-CSF) on hemopoietic stem cells in vivo were investigated. The experiments were performed on mice using the e ndogenous spleen colony formation in gamma-irradiated animals as an endpoin t. The results have shown that DP and AMP act additively with G-CSF to enha nce spleen colony formation and thus the erythroid repopulation of the sple en. These findings indicate that the signaling pathways of G-CSF and drugs elevating extracellular adenosine can interact at the level of primitive he mopoietic stem cells. The enhancement of hemopoiesis-stimulating effects of G-CSF by DP and AMP, which are low-priced and clinically available drags, could improve the cost-effectiveness of the therapy with G-CSF.