Udupa K B, Lipschitz D A
J Lab Clin Med. 1984 Apr;103(4):574-80.
Changes in erythropoiesis with age were studied by examining the hematocrit increase in response to hypoxia in aged mice and by assessing the change in erythropoiesis following the injection of erythropoietin in young and old polycythemic mice. The increase in hematocrit after exposure to hypoxia was more variable and generally lower in old mice than in young mice. When erythropoietin was injected into polycythemic animals, the increase in differentiated erythroid cells and 59Fe incorporation into erythroid marrow and peripheral blood cells was significantly lower in old mice than in young mice. In contrast to differentiated erythroid cells, there was less evidence of a reduced response to stimulation of the more primitive erythroid progenitor cells of aged animals. The early undifferentiated erythroid progenitor, burst-forming units, did not decrease when either young or aged mice were made polycythemic, and no change following erythropoietin injection was noted. Polycythemia suppressed the late-differentiated erythroid progenitor, erythroid colony-forming units, to a greater extent in aged animals, but when erythropoietin was injected, the percent increase over the subsequent 24 hours was identical to that in young mice. These observations indicate a reduced erythropoietic capacity with age, the abnormality being most obvious in the more mature erythroid precursors.
通过检测老年小鼠对低氧的血细胞比容增加情况，以及评估年轻和老年红细胞增多症小鼠注射促红细胞生成素后红细胞生成的变化，研究了红细胞生成随年龄的变化。暴露于低氧后，老年小鼠的血细胞比容增加更具变异性，且通常低于年轻小鼠。当向红细胞增多症动物注射促红细胞生成素时，老年小鼠中分化的红系细胞增加以及59Fe掺入红系骨髓和外周血细胞的量显著低于年轻小鼠。与分化的红系细胞相反，老年动物更原始的红系祖细胞对刺激的反应降低的证据较少。当年轻或老年小鼠发生红细胞增多症时，早期未分化的红系祖细胞，即爆式形成单位，并未减少，注射促红细胞生成素后也未观察到变化。红细胞增多症在老年动物中对晚期分化的红系祖细胞，即红细胞集落形成单位的抑制作用更大，但注射促红细胞生成素后，随后24小时的增加百分比与年轻小鼠相同。这些观察结果表明，随着年龄增长，红细胞生成能力下降，这种异常在更成熟的红系前体细胞中最为明显。
