Calyculin A诱导早熟染色体凝聚的电离辐射剂量效应曲线

以Calyculin A诱导早熟染色体凝聚(PCC)方法,探索G2/M-PCC细胞中PCC环用于分析电离辐射损伤程度的可行性,用0—20 Gy(剂量率为1 Gy/min)的60Coγ射线照射外周血,培养48 h并用Calyculin A诱导PCC。分析各剂量点G2/M-PCC指数、判断观察到的PCC环是否符合泊松分布,建立PCC环率与剂量之间的剂量效应曲线。结果发现,用Calyculin A可成功诱导人外周血淋巴细胞产生PCC,且G2/M-PCC指数随着剂量水平的增高而降低。除20 Gy剂量外,0—16 Gy各剂量点样品中PCC环的分布符合泊松分布。PCC环率随着剂量增加而增加,剂量-效应曲线可以拟合成y=0.0128x+0.0104直线方程,测得R2=0.9898(y为PCC-R率,x为剂量);二次多项式方程为y=0.00002x2+0.0085x+0.0011 R2=0.9996。由此可见,Calyculin A诱导淋巴细胞G2/M-PCC中的PCC环率可用于生物体电离辐射损伤程度测定。

Establishment of the dose-effect curve between Calyculin A induced premature chromosome condensation ring and exposed dose

In order to explore the probability of PCC-ring（PCC-R） in G2/M-PCC cells could be used to quantify the extent of ionizing radiation damage,premature chromosome condensation（PCC） induced by Calyculin A was analyzed.Peripheral blood samples were irradiated with 0,4,8,12,16 and 20 Gy 60Coγ-rays.The PCC-R,which was induced by Calyculin A after culture of 48 h,was observed in the samples exposed to different dose of 60Co γ-rays.The G2/M-PCC index and the distribution of PCCR were calculated;the dose-response curves between the frequency of PCC-R and exposed dose level were established.The results showed that PCC was successfully induced by Caly-culin A.The G2/M-PCC index decreased with exposed dose level.The PCC-R distribution followed a Poisson law for most of dose levels except 20 Gy.The frequency of PCC-R increased with the exposed dose level.And the dose-effect curve between the frequency of hollow-,kidney-shape ring and exposed dose level was fitted with two models,a linear model y=0.0128x＋0.0104 R2=0.9898 and a non-linear model y=0.00002x2＋0.0085x＋0.0011 R2=0.9996.The frequency of PCC-R in peripheral blood lymphocyte G2/M-PCC cells induced by Calyculin A could be used to quantify the extent of ionizing radiation damage.