Inoue T, Bullis J E, Cronkite E P, Hübner G E
Proc Natl Acad Sci U S A. 1983 Jan;80(2):435-8. doi: 10.1073/pnas.80.2.435.
Graded numbers of bone marrow (BM) cells were injected into fatally irradiated mice. Eight days later the mice were given 3.0 microCi (1 Ci = 3.7 X 10(10) Bq) of 125IdUrd to label proliferating cells in the spleen and BM. On day 9 the mice were killed and the spleens and femurs were removed for splenic colony assay and measurement of radioactivity in the spleen and femurs. The number of splenic colonies shows a linear relationship with dose of marrow cells injected from 10(4) to 10(5) cells. The slope of the curve of spleen colonies versus number of cells injected is less than 1, implying that the fraction seeded in spleen decreases with number of cells injected. Above 10(5) and below 10(4) there is a striking departure from the simple linearity. Below 2 X 10(3) cells injected, the logarithm of the observed colony yield is linear with logarithm of the number of cells injected. Poisson calculation of the average number of pluripotent stem cells that should be present with numbers of marrow cells injected below 2 X 10(3) followed closely the actual observations. The data show that there is no detectible proliferation in the BM until the dose of marrow cells exceeds 3.5 X 10(4) cells. Induction of cells into cycle increases the seeding into the BM, and thymidine cytocide drastically reduces seeding in the BM, leading us to conclude that the BM is repopulated almost exclusively by stem cells in DNA synthesis.
将不同数量级的骨髓（BM）细胞注入受到致死性照射的小鼠体内。八天后，给小鼠注射3.0微居里（1居里 = 3.7×10¹⁰贝克勒尔）的¹²⁵碘脱氧尿苷来标记脾脏和骨髓中增殖的细胞。在第9天处死小鼠，取出脾脏和股骨进行脾集落测定以及测量脾脏和股骨中的放射性。脾集落数量与注入的骨髓细胞剂量在10⁴至10⁵个细胞之间呈线性关系。脾集落曲线与注入细胞数量的斜率小于1，这意味着接种到脾脏中的细胞比例随注入细胞数量的增加而降低。在10⁵以上和10⁴以下，明显偏离了简单的线性关系。注入细胞数量低于2×10³时，观察到的集落产量的对数与注入细胞数量的对数呈线性关系。对注入细胞数量低于2×10³时应存在的多能干细胞平均数量进行泊松计算，结果与实际观察结果密切相符。数据表明，直到骨髓细胞剂量超过3.5×10⁴个细胞时，骨髓中才会出现可检测到的增殖。将细胞诱导进入细胞周期会增加向骨髓中的接种量，而胸苷细胞毒素会大幅降低向骨髓中的接种量，这使我们得出结论，骨髓几乎完全由处于DNA合成阶段的干细胞重新填充。
