Zhang R X, Nagashima T, Hoshino T
Department of Neurological Surgery, University of California School of Medicine, San Francisco.
Cell Tissue Kinet. 1987 May;20(3):357-62. doi: 10.1111/j.1365-2184.1987.tb01317.x.
The magnitude of DNA modulation in rat 9L gliosarcoma cells after a brief exposure to bromodeoxyuridine (BrdU) was studied by assaying colony-forming efficiency (CFE) and the number of sister chromatid exchanges (SCEs) per metaphase. The CFE assay showed that a 1-hr exposure to BrdU, at concentrations ranging from 10 to 1000 microM, produced a maximum cell kill of 5%. After a 2-hr exposure to 20 microM BrdU, the surviving fraction was 0.99, and even at a BrdU concentration of 1000 microM, 77% of the 9L cells survived. Compared with control cultures, the relative number of SCEs per metaphase in treated cultures was increased after a 1-hr exposure to BrdU at concentrations of 100 microM or more and after a 2-hr exposure to concentrations of 20 microM or more; no increase was observed in cells treated for 30 min with BrdU at concentrations up to 1000 microM. When the treated cells were allowed to grow in BrdU-free growth medium, the number of SCEs per metaphase returned to the control level within 24 hr, even after exposure to BrdU at concentrations as high as 1000 microM. These results demonstrate that exposure to BrdU at concentrations of up to 1000 microM for 30 min, 100 microM for 1 hr, and 20 microM for 2 hr causes little modulation of DNA.
通过测定集落形成效率（CFE）和每个中期的姐妹染色单体交换（SCE）数量，研究了大鼠9L胶质肉瘤细胞短暂暴露于溴脱氧尿苷（BrdU）后DNA调节的程度。CFE分析表明，在10至1000 microM的浓度下暴露于BrdU 1小时，最大细胞杀伤率为5%。在20 microM BrdU中暴露2小时后，存活分数为0.99，即使在BrdU浓度为1000 microM时，77%的9L细胞存活。与对照培养物相比，在100 microM或更高浓度下暴露于BrdU 1小时以及在20 microM或更高浓度下暴露2小时后，处理培养物中每个中期的SCE相对数量增加；在高达1000 microM的浓度下用BrdU处理30分钟的细胞中未观察到增加。当处理后的细胞在不含BrdU的生长培养基中生长时，即使在高达1000 microM的浓度下暴露于BrdU后，每个中期的SCE数量在24小时内恢复到对照水平。这些结果表明，在高达1000 microM的浓度下暴露于BrdU 30分钟、100 microM 1小时和20 microM 2小时对DNA的调节作用很小。
