用Calyculin—A诱导的早熟染色体凝集技术研究了γ射线诱导人肝癌细胞株HepG2细胞G2期染色体的原初损伤。结果表明:G2等点染色单体断裂畸变与辐射剂量呈线性平方关系,G2染色单体断裂畸变和G2期染色单体断裂畸变总数与辐射剂量呈线性正相关关系,发生各类断裂畸变的细胞率与剂量也呈线性正相关关系。γ射线诱发的断裂畸变主要是G2染色单体断裂畸变,断裂畸变的细胞主要是发生G2染色单体断裂畸变。
A chemically induced premature chromosome condensation technique with Calyculin-A has been employed to estimate the initial chromosome damage in HepG2 condensed in G2 phase and the percentage of aberrant cells after exposure to γ-rays. The results show that the dose-response for iso-chromatid breaks is linear-quadratic manner, while chromatid-type breaks and total chromatid breaks show a positive linear dose-response. The percentages of all kinds of aberrant cells are increasing linearly with increasing doses. G2 chromatid-type breaks and the percentage of G2 chromatid-type aberrant cells are predominate in G2 total chromatid breaks induced by γ-rays.