Abkowitz Janis L, Catlin Sandra N, McCallie Monica T, Guttorp Peter
Departments of Medicine and Statistics, University of Washington, Seattle; and the Department of Mathematical Statistics, University of Nevada, Las Vegas.
Blood. 2002 Oct 1;100(7):2665-7. doi: 10.1182/blood-2002-03-0822.
Humans and larger mammals require more blood cells per lifetime than mice because of their larger size and longer life expectancy. To investigate this evolutionary adaptation, we calculated the total number of nucleated marrow cells (NMCs) per cat, observing the distribution of (59)Fe to marrow, then multiplied this value (1.9 +/- 0.9 x 10(10) [mean +/- SD]) times the frequency of feline hematopoietic stem cells (HSCs) (6 HSCs/10(7) NMCs) to derive the total number of HSCs per cat (11 400 +/- 5400). Surprisingly, when the total number of HSCs per mouse was calculated with a similar experimental and computational approach, the value was equivalent. These data imply that the output of differentiated cells per feline HSC must vastly exceed that of murine HSCs. Furthermore, if the total number of human HSCs were also equivalent to the total number of HSCs in cat and mouse, the frequency of human HSCs would be 0.7 to 1.5 HSCs/10(8) NMCs, a frequency that is 20-fold less than estimated by the NOD/SCID repopulating assay.
由于人类和大型哺乳动物体型更大、预期寿命更长，其一生中所需的血细胞比小鼠更多。为了研究这种进化适应性，我们计算了每只猫有核骨髓细胞（NMC）的总数，观察（59）Fe在骨髓中的分布，然后将该值（1.9±0.9×10¹⁰[平均值±标准差]）乘以猫造血干细胞（HSC）的频率（6个HSC/10⁷个NMC），得出每只猫HSC的总数（11400±5400）。令人惊讶的是，当用类似的实验和计算方法计算每只小鼠HSC的总数时，得到的值是相同的。这些数据表明，每只猫HSC分化细胞的输出量必定大大超过小鼠HSC。此外，如果人类HSC的总数也与猫和小鼠HSC的总数相当，那么人类HSC的频率将为0.7至1.5个HSC/10⁸个NMC，该频率比NOD/SCID重建造血试验估计的频率低20倍。
