Morales-Ramírez P, Cruz-Vallejo V L, Vallarino-Kelly T, Rodríguez-Reyes R
Departamento de Radiobiología, Instituto Nacional de Investigaciones Nucleares, México, D.F., México.
Somat Cell Mol Genet. 1995 Jan;21(1):33-41. doi: 10.1007/BF02255820.
The efficiency of mitomycin C or gamma rays to induce SCE in early or late G1 was determined in synchronized murine salivary gland cells in vivo, as a measure of the capacity of this tissue to repair the lesions involved in SCE formation before S. The SCE frequencies induced by MMC in the first division (before BrdU incorporation) were significantly lower in the early G1 compared to the late G1, indicating some repair of SCE-inducing lesions. In the second division (after BrdU incorporation), there was no difference between SCE induced in early and late G1, indicating that MMC-induced lesions in such conditions are very persistent and not repairable during G1. The radio induced SCE frequency at early G1 was significantly lower than that observed in late G1, in cells irradiated after BrdU incorporation, suggesting that half of gamma ray-induced DNA lesions that elicit SCEs were repaired.
在体内同步化的小鼠唾液腺细胞中，测定了丝裂霉素C或γ射线在G1期早期或晚期诱导姐妹染色单体交换（SCE）的效率，以此作为该组织在S期之前修复SCE形成过程中所涉及损伤能力的一种衡量指标。与G1期晚期相比，丝裂霉素C在第一次分裂（在掺入溴脱氧尿苷之前）诱导的SCE频率在G1期早期显著更低，这表明SCE诱导损伤有一定程度的修复。在第二次分裂（在掺入溴脱氧尿苷之后），G1期早期和晚期诱导的SCE之间没有差异，这表明在这种情况下丝裂霉素C诱导的损伤非常持久，在G1期不可修复。在掺入溴脱氧尿苷后照射的细胞中，G1期早期的辐射诱导SCE频率显著低于G1期晚期观察到的频率，这表明引发SCE的γ射线诱导的DNA损伤有一半得到了修复。
