Pluthero F G, van der Gaag H, Eskinazi D
Department of Anatomy, University of Toronto, Canada.
Int J Hematol. 1991 Oct;54(5):357-62.
Mice of the C57BL/6 (B6) strain show a much lower proportion of marrow erythroid progenitor cells (BFU-E) in DNA synthesis in vivo than mice of the congeneic B6S strain. However, when assayed in vitro marrow cells from both strains show high proportions of BFU-E in S-phase. BFU-E from normal B6 mice have been previously shown to be specifically inhibited from entering S-phase in vitro by the antioxidant enzyme superoxide dismutase (SOD), however, in this study we have found that BFU-E taken from the marrow of B6S mice or B6 mice which have been subjected to bleeding are insensitive to SOD inhibition in vitro. Comparisons of results from in vivo and in vitro cycling assays done with cells from both strains indicate that a large proportion of marrow BFU-E in normal B6 mice are halted in the pre-S portion of the cell cycle in vivo, and these halted cells are prevented from going into S-phase in vitro by SOD. The insensitivity to SOD inhibition shown by BFU-E from B6S and bled B6 mice can be attributed to the absence of accumulation of SOD-susceptible cells in pre-S phase in these mice in vivo, and there is evidence to suggest that the difference in BFU-E cycling seen in vivo may be due to interactions between SOD and factors which stimulate cycling of BFU-E.
C57BL/6（B6）品系的小鼠体内骨髓红系祖细胞（BFU-E）进行DNA合成的比例比同基因B6S品系的小鼠低得多。然而，当对两个品系的骨髓细胞进行体外检测时，处于S期的BFU-E比例都很高。先前已表明，正常B6小鼠的BFU-E在体外会被抗氧化酶超氧化物歧化酶（SOD）特异性抑制进入S期，然而，在本研究中我们发现，取自B6S小鼠或经历过出血的B6小鼠骨髓的BFU-E在体外对SOD抑制不敏感。对两个品系细胞进行的体内和体外循环分析结果的比较表明，正常B6小鼠体内大部分骨髓BFU-E在细胞周期的S期前阶段停滞，并且这些停滞的细胞在体外会被SOD阻止进入S期。B6S和出血B6小鼠的BFU-E对SOD抑制不敏感，这可归因于这些小鼠体内S期前阶段不存在对SOD敏感的细胞积累，并且有证据表明，体内观察到的BFU-E循环差异可能是由于SOD与刺激BFU-E循环的因子之间的相互作用。
