Radiosensitivity test during low dose rate irradiation in normal and repair deficient cells

我们将正常和共济失调毛细血管扩张细胞暴露于每天0.5戈伊的γ射线。在照射期间将细胞维持在G 0下。剂量为1 ~ 3戈伊，用融合早熟染色体凝集技术分析染色体畸变。Giemsa染色显示，1戈伊在正常细胞中诱导约0.36个碎片，在AT细胞中诱导约1.35个碎片，表明AT细胞比正常细胞更不有效地重新连接断裂。我们还使用FISH技术分析了暴露于3戈伊后的染色体交换。AT细胞有更多的错位断裂。经3戈伊照射的细胞传代培养后，用Calyculin-A诱导的PCC技术分析G2期染色体畸变，两种细胞系中未连接断裂减少，错接断裂增加，提示AT细胞开始重新连接断裂时，在G 0期AT细胞中观察到一定数量的鸟嘴，并观察到交换次数的增加，这与高剂量率照射后的情况相似

We exposed normal and ataxia telangiectasia cells to 0.5 Gy per day to gamma ray. Cells were maintained under Go during irradiation. The dose was 1 to 3 Gy and chromosomal aberrations using fusion premature chromosomal condensation technique were analyzed. Giemsa staining showed that 1 Gy induces around 0.36 fragments in normal cells and around 1.35 in AT cells, indicating that AT cells rejoin breaks less effectively than normal cells. We also analyzed chromosomal exchange after exposure to 3 Gy using FISH techniques. AT cells have more misrejoined breaks. When cells irradiated with 3 Gy were subcultured and G2 chromosomal aberrations were analyzed using calyculin-A induced PCC technique, unrejoined breaks decreased and misrejoined breaks increased in both cell lines, suggesting that AT cells begin to rejoin breaks when a certain number of beaks are accumulated and an increased number of exchanges were observed in G0 AT cells, which is similar situation after high-dose-rate irradiation