title: Apparent heterogeneity of human megakaryocyte colony- and thrombopoiesis-stimulating factors: studies on urinary extracts from patients with aplastic anaemia and idiopathic thrombocytopenic purpura.
abstract: Megakaryocyte colon-stimulating factor (MEG-CSF) in the urinary extracts from patients wit aplastic anaemia (AA) revealed two distinct peaks of activity on Sephadex G-200 gel filtration with apparent molecular weights of 155,000 and 76,000. Both fractions induced significant thrombocytosis in peripheral blood and megakaryocytosis in the spleen of rats. Heterogeneity of MEG-CSF was also found in the extracts from the urine of patients with idiopathic thrombocytopenic purpura. The higher molecular weight MEG-CSF was significantly reduced when the gel filtration was performed under the dissociating conditions. Ion-exchange chromatography indicated that the higher molecular weight MEG-CSF had a different charge from the lower molecular weight MEG-CSF. These results suggest that the apparent heterogeneity of MEG-CSF is due to interaction of MEG-CSF with other proteins in the urinary extracts.
mesh_terms: D000741:Anemia, Aplastic / Q000652:urine*; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D003115:Colony-Stimulating Factors / Q000652:urine*; D006801:Humans; D008533:Megakaryocytes; D008970:Molecular Weight; D011696:Purpura, Thrombocytopenic / Q000652:urine*
chemical_list: D003115:Colony-Stimulating Factors