| Project/Area Number |
61560094
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
応用生物化学・栄養化学
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| Research Institution | Kyoto University |
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Principal Investigator |
RYUZO Sasaki Dept. of Food Sci. and Technol., Faculty of Agriculture, Kyoto Univ., 農学部, 助教授 (60077378)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| 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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| Keywords | Erythropoietic factors / Burst-promoting activity / Erythropoietin / Purification / Human urine / 赤血球分化 / 赤血球前駆細胞 |
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| Research Abstract |
Two distinct growth factors are needed for erythropoiesis. Erythropoietin (Ep) promotes both the growth of late erythroid precursor cells (CFU-E) and their maturation into proerythroblasts in which hemoglobin (Hb) synthesis is initiated. The other factor, burst-promoting activity (BPA) acts on the early precursor cells (BFU-E) and is responsible for differentiation of these cells into CFU-E with high responsiveness to Ep. This project was aimed at purifying BPA from a human source and exploring the effects of the two factors, BPA and Ep, on erythroid burst-colony formation of human peripheral blood mononuclear cells in methlycellulose cultures. Ep was isolated from the urine of patients with aplastic anemia and BPA was found in the resiue obtained after removal of Ep. Extensive purification of BPA yielded a preparation of BPA completely free from Ep. Reddish bursts were formed with the addition of Ep alone. Addition of BPA not only elevated the number of bursts but also grealty reduced the amount of Ep reqiured for burst formation. The presence of BPA alone in cultures did not permit bursts to form but did permit the growth of small colonies that did not contain Hb. Addition of Ep to these small colonies led to the formation of erythroid bursts. Administration of Ep to the culture could be delayed for 6 days without decreasing the number of bursts if the cultures were initiated in the presence of BPA; in the absence of BPA, BFU-E were repidly lost if Ep was not provided at the start of the culture. BPA produced larger bursts than those formed in the presence of Ep alone. Microassays of Hb in the bursts indicated that BPA increased the amount of Hb per burst. This increase could not be entirely explained by the augumentation in cell number per burst but was partly ascribable to the increased amount of Hb. per cell.
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