| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
We previously reported the presence of thrombopoietin (Tpo) and megakaryocyte colony stimulating factor (Meg-CSF) in the urinary extract from patients with aplastic anemia. Since AA urinary extract contains a large amount of erythropoietin (Epo), it was investigated initially whether or not recombinant Epo augments murine megakaryopoiesis.
In serum-free culture using nonadherent, nonphagocytic and T-cell depleted marrow cells, twice as many single megakaryocytes and two cell aggregates were generated by Epo than generated by pokeweed mitogen-stimulated spleen cell conditioned medium (PWM-SCM).
The number of colonies with four or more cells formed by PWM-SCM, however, was significantly higher than those stimulated by Epo.
When administered to rats, Epo induced a significant increase in the diameter of megakaryocytes in the bone marrow on day 7. In addition, an increase in the size of platelets in the peripheral blood was also found in Epo-treated rats.
These results suggest that Epo influence on rather late phase of megakaryopoiesis.
Next, partial purification of urinary Meg-CSF was performed using an immunoadsorbent column of anti-Epo IgG.
Comparison of Meg-CSF activity by recombinant Epo and pass through fraction from anti-Epo column suggests the presence of a Meg-CSF, which is distinct from Epo. Finally we tried to establish an assay method for Tpo in vitro.
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