A Quantitative Study on the Rate of Cell Production in the Bone Marrow of Young Mature Albino Rats.
1960 年 35 巻 5-6 号 p. 375-402
詳細
1960 年 35 巻 5-6 号 p. 375-402
1. In an attempt to make possible a direct calculation of the total number of cells newly produced by mitosis per day in the bone marrow, a series of determinations have been made of the mitotic index of bone marrow of young mature male albino rats weighing around 200g, before and at successive intervals after the subcutaneous injection of colchicine in a dose of 0.10 mg per 100 g of body weight.
2. Normal values of the mitotic index of bone marrow were found to be for the erythrocytic series 36.1±2.8 per thousand nucleated red cells and for the granulocytic series 8.9±1.1 per thousand granulocytes (14.8±2.4 per thousand non-segmented granulocytes).
3. The total percentages of mitoses per day were estimated to be 134.8-151.6% for the erythrocytic series,23.9-25.4% for the total granulocytes,26.0-28.0% for the neutrophils and 6.6-8.3% for the eosinophils; whereas the corresponding figures for the late form s alone were 105.4-122.5% for the erythrocytic series,10.6-11.3% for the total granulocytes, and 11.6-12.3% for the neutrophils.
4. Using the data of Awaya et al. (1960 ) on the total number of nucleated cells in the whole marrow, the average numbers of mitoses per day were computed to be (3,104-3,190)×106 for the erythrocytic series, (641-664)×106 for the total granulocytes, (614-547)×106 for the neutrophils, and (16.8-25.2)×106 for the eosinophils When mitoses of the late forms alone were taken into accunt, the corresponning figures turned out to be (2,418-2,579)×106 for the erythrocytic series, (287-294)×106 for the total granulocytes, and (271-291)×106 for the neutrophils.
5. On the basis of an assumption that only the late forms of bone marrow elements are the direct supply source of the circulating blood cells and using the data of Mon den (1959b) on total cellular numbers in the blood, the turnover times of cell populations in the blood were calculated to be 0.165-0.169 day (about 4hours) for the total granulocytes,0.161-0.172 day for the neutrophils,0.125-0.250 day for the eosinophils, and 44-47 days for the erythrocytes.
6. By a direct calculation from the figures obtained for the daily mitotic rates, the turnover time of each type of blood cells in the bone marrow was estimated to be 3.94-4.19 days for the total granulocytes (2.3 day for the non-segmented granulocytes),3.56-3.84 days for the neutrophils (1.9 days for the non-segmented neutrophils),12-15 days for the eosinophils, and 0.66-0.74 day for the nucleated red cells.
7. Besides, an indirect calculation of the turnover times of cell populations in the bone marrow was also made from Hoffman's formula, assuming that the mitotic time of dividing cells is of 1-hour or of 30-minute duration.
