COMPARISON OF INTESTINE AND BONE-MARROW RADIOSENSITIVITY OF THE BALB/C AND THE C57BL/6 MOUSE STRAINS AND THEIR B6CF1 OFFSPRING
COMPARISON OF INTESTINE AND BONE-MARROW RADIOSENSITIVITY OF THE BALB/C AND THE C57BL/6 MOUSE STRAINS AND THEIR B6CF1 OFFSPRING
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DOI：
10.2307/3577002
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发表时间：
1987-06-01
影响因子：
3.4
通讯作者：
AINSWORTH, EJ
中科院分区：
文献类型：
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作者：
HANSON, WR;FRY, RJM;AINSWORTH, EJ
以F1杂交体B6CF1 （C57BL/6）的LD50/6或LD50/30测量放射灵敏度。BALB/c)与C57BL/6小鼠相似，但与BALB/c有显著差异。BALB/c小鼠的LD50/6约为8.8 Gy，而B6CF1为16.4 Gy。亲本株之间或BALB/c与F1杂交株之间LD50/6的差异不能用隐窝细胞数量、细胞周期时间或运输时间的差异来解释。同样，观察到的LD50/6的差异似乎不是由于骨髓干细胞（CFU-S）放射敏感性的显着差异造成的，因为三种基因型小鼠的D0' s相似。此外，红细胞中几种与抗氧化防御相关的酶的含量也没有明显差异。用微落法测定隐窝结肠菌细胞的D0和60Co . γ的D0值。BALB/c小鼠为0.8 Gy， B6CF1小鼠为1.4 Gy。然而，JANUS裂变中子的D0值是相似的；BALB/c小鼠为0.6 Gy， B6CF1小鼠为0.5 Gy。克隆源细胞动力学的比较，使用延长的秋碱阻断区分缓慢和快速循环的细胞表明，通常情况下，干细胞在BALB/c和B6CF1杂交中都是缓慢循环的。然而，B6CF1的干细胞似乎比BALB/c的干细胞在照射或长时间的秋碱治疗后更快地进入快速细胞周期。辐照后B6CF1杂交小鼠肠上皮细胞生成的更快恢复可能提供了更强的粘膜屏障，这可能部分解释了与BALB/c相比对辐射反应的差异。
The radiosensitivity as measured by LD50/6 or LD50/30 of the F1 hybrid B6CF1 (C57BL/6 .times. BALB/c) is similar to that of C57BL/6 mice but markedly different from BALB/c. The LD50/6 for BALB/c mice was about 8.8 Gy compared to 16.4 Gy for the B6CF1. The difference in LD50/6 between the parent strains or between BALB/c and the F1 hybrid could not be explained by any differences in crypt cell number, cell cycle time, or transit time. Likewise, the observed differences in the LD50/6 do not appear to result from marked differences in the radiosensitivity of marrow stem cells (CFU-S) since the D0''s for the three genotypes of mice were similar. Also, there were no apparent differences in the red blood cell contents of several enzymes associated with antioxidant defenses. The microcolony was used to determine the D0 for the crypt colonogenic cells and the D0 values for 60Co .gamma. rays were about 0.8 Gy for BALB/c mice and 1.4 Gy for B6CF1 mice. However, the D0 values for JANUS fission neutrons were similar; 0.6 Gy for the BALB/c mice and 0.5 for the B6CF1 mice. A comparison of clonogenic cell kinetics, using prolonged colcemid block to distinguish between slowly and rapidly cycling cells suggest that, normally, the stem cells are slowly cycling in both the BALB/c and the B6CF1 hybrid. However, the stem cells of the B6CF1 appear to go into rapid cell cycle more rapidly than those of the BALB/c following irradiation or prolonged colcemid treatment. The more rapid recovery in intestinal epiphelial cell production in the B6CF1 hybrid after irradiation may provide an increased mucosal barrier and may, in part, explain the difference in the response to radiation compared to that in the BALB/c.