【摘要】 研究了人肝癌细胞SMMC7721在低剂量γ射线照射下超敏感性和增强的辐射抗性响应。选用对数生长期细胞接受0—6Gy不同剂量的60Coγ射线的照射。利用流式细胞仪对细胞进行分选计数,并用克隆形成法检测细胞存活率。发现SMMC7721细胞存在低剂量辐射超敏感性和增强的辐射抗性响应,即在0—0.3Gy之间细胞表现出单位剂量杀伤增强现象,在0.3—1Gy细胞表现一定的辐射抗性,在1Gy以上,细胞的存活符合线性平方模型。更多还原

【Abstract】 The low-dose responses such as hypersensitivity and increased radio-resistance of human hepatoma SMMC-7721 cells were studied in this work. Exponentially growing SMMC-7721 cells were irradiated with ⁶⁰Co γ-rays at doses of 0—6 Gy. Together with flow cytometer for precise cell sorting, cell survival fractions were measured by means of conventional colony-formation assay. It has been found that the SMMC-7721 cells showed hyper-radiosensitivity response at low doses and increased radio-resistance at larger single doses. There was an excessive cell killing per unit dose when the doses were below about 0.3 Gy, and the cells exhibited more resistant response at the doses between 0.3 and 1.0 Gy. When the single dose was beyond 1.0 Gy, the cell survival agreed well with the prediction of the commonly accepted linear-quadratic model.更多还原