Mivechi N F, Li G C
Cancer Res. 1986 Jan;46(1):198-202.
We have studied the sensitivities of four hematopoietic stem cell types to heat stress as well as their abilities to develop thermotolerance. Granulocyte-macrophage colony forming units were the most heat resistant bone marrow progenitors tested. Of the erythroid progenitors tested, erythrocyte colony forming units were more resistant than the two more primitive erythrocyte burst forming units. To determine their ability to develop thermotolerance, hematopoietic precursors were heated in vivo at 43 degrees C for 30 min. At various times thereafter the hematopoietic stem cells were flushed from female C3Hf/Sed mouse preheated tibia. The bone marrow cell suspensions were then heated in vitro and plated for colony formation. The four stem cell precursors differed markedly in their abilities to develop thermotolerance. The thermotolerance induced in granulocyte-macrophage colony forming units reached a maximum at 3-6 h after heating and disappeared by 24-48 h. The thermotolerance in erythrocyte colony forming units (0.5 units erythropoietin/ml media) reached a maximum at 3-6 h and disappeared by 48-72 h. The maximum level of thermotolerance reached by granulocyte-macrophage colony forming units and erythrocyte colony forming units was approximately the same. On the contrary, the two more primitive erythrocyte precursors which were grown by the addition of 2.5 and 5 units erythropoietin/ml of media do not develop thermotolerance.
我们研究了四种造血干细胞类型对热应激的敏感性及其产生耐热性的能力。粒细胞-巨噬细胞集落形成单位是所测试的最耐热的骨髓祖细胞。在所测试的红系祖细胞中，红细胞集落形成单位比另外两种更原始的红细胞爆式集落形成单位更具抗性。为了确定它们产生耐热性的能力，造血前体细胞在体内于43℃加热30分钟。此后在不同时间从预热的雌性C3Hf/Sed小鼠胫骨中冲洗出造血干细胞。然后将骨髓细胞悬液在体外加热并接种用于集落形成。这四种干细胞前体在产生耐热性的能力上有显著差异。粒细胞-巨噬细胞集落形成单位诱导的耐热性在加热后3 - 6小时达到最大值，并在24 - 48小时消失。红细胞集落形成单位（0.5单位促红细胞生成素/毫升培养基）的耐热性在3 - 6小时达到最大值，并在48 - 72小时消失。粒细胞-巨噬细胞集落形成单位和红细胞集落形成单位达到的最大耐热水平大致相同。相反，通过添加2.5和5单位促红细胞生成素/毫升培养基培养的另外两种更原始的红细胞前体不会产生耐热性。
