title: Effect of human recombinant erythropoietin on human marrow megakaryocyte colony formation in vitro.
abstract: The effect of human recombinant erythropoietin (EP) on the growth of human marrow megakaryocyte colony forming units (CFU-M) in vitro was investigated by the use of a plasma clot assay. EP as a single stimulating factor or as an additional factor to optimal concentration of leucocyte conditioned medium (PHA-LCM) had no effect on the number of CFU-M derived colonies. However, addition of EP (0.5-1 U/ml) to cultures with suboptimal concentrations of PHA-LCM increased megakaryocytic colony formation by 50-90% but had no effect on the number of granulocytic-monocytic colonies (CFU-GM). Exposure of marrow cells to EP for 24-48 h in liquid suspension cultures, followed by removal of the hormone and assaying the cells for CFU-M in plasma clots, resulted in a 50-100% increase of megakaryocyte colony formation in vitro. The augmenting effect of EP on CFU-M growth in vitro was abolished when EP was added to the medium after the third day of culture. The presence of factors in human serum and in PHA-LCM was an absolute requirement for the hormone to exert its potentiating effect on human CFU-M growth in vitro. Recombinant EP potentiates the growth of human marrow CFU-M and this effect seems to be exerted during the early stages of CFU-M development in vitro.
mesh_terms: D000328:Adult; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D002478:Cells, Cultured; D003470:Culture Media; D004921:Erythropoietin / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D003470:Culture Media; D010835:Phytohemagglutinins; D011994:Recombinant Proteins; D004921:Erythropoietin