Ludwików G, Ludwików F, Johanson K J
Department of Radioecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Radiat Res. 1994 Apr;138(1):70-8.
The kinetics of the formation of cells carrying micronuclei (MN) after one doubling time (td) incorporation of 125I-iododeoxyuridine (125IdU) to Chinese hamster ovary (CHO) and rat anterior pituitary tumor (GC) cells was studied. Uptake of 125IdU by cells of both cell lines was linearly dependent on the concentration of extracellular 125I activity. The postlabeling time-dependent decrease in cellular activity of 125IdU was exponential in CHO cells and approximately linear in GC cells. The maximum yield of MN was seen during the second and third td after 125IdU incorporation. The frequency of cells with micronuclei increased monotonically with dose in the interval (1, 40) 125I decays cell-1td-1. The dose-response relationship could be fitted by straight lines with slopes of 1.0 (CHO) and 1.2 (GC) on the subinterval (1, 10) and of 0.6 or 0.5, respectively, for the subinterval (10, 40). Below one 125I decay cell-1td-1, the mean frequency of micronucleated binuclear cells was significantly lower than (CHO) or equal to (GC) the control. On average, one 125I decay/cell induced 0.95 +/- 0.5% (CHO) or 1.0 +/- 0.5% (GC) of micronucleated binuclear cells.
研究了将¹²⁵I-碘脱氧尿苷（¹²⁵IdU）掺入中国仓鼠卵巢（CHO）细胞和大鼠垂体前叶肿瘤（GC）细胞一倍增时间（td）后，携带微核（MN）的细胞形成动力学。两种细胞系的细胞对¹²⁵IdU的摄取与细胞外¹²⁵I活性浓度呈线性相关。¹²⁵IdU细胞活性的标记后时间依赖性下降在CHO细胞中呈指数形式，在GC细胞中近似呈线性。¹²⁵IdU掺入后，在第二个和第三个td观察到微核的最大产量。在（1, 40）¹²⁵I衰变·细胞⁻¹·td⁻¹的区间内，有微核的细胞频率随剂量单调增加。剂量-反应关系在子区间（1, 10）上可由斜率为1.0（CHO）和1.2（GC）的直线拟合，在子区间（10, 40）上分别为0.6或0.5。低于1¹²⁵I衰变·细胞⁻¹·td⁻¹时，双核微核细胞的平均频率显著低于（CHO）或等于（GC）对照组。平均而言，每细胞一次¹²⁵I衰变诱导0.95±0.5%（CHO）或1.0±0.5%（GC）的双核微核细胞。
