Induction of neoplastic transformation by low-dose-rate exposure to tritiated water.
Induction of neoplastic transformation by low-dose-rate exposure to tritiated water.
复制标题
通过低剂量率接触氚水诱导肿瘤转化。
作者：
J. Little
以低密度接种指数生长的小鼠BALB/3T3细胞，用不同浓度的氚水(3HOH)孵育。在含有25-500微克/毫升3HOH的细胞中孵育100小时，转化子产量呈剂量依赖性增加。剂量-反应曲线在低剂量时呈线性上升，没有阈值或二次分量的证据。相同总剂量照射5~168h的转化频率相似，但照射5h的存活率略低于间隔时间较长的照射。在200-400拉德剂量下，急性X射线照射在诱导转化方面似乎比长期暴露在3HOH中更有效，但在25-100拉德范围内的效果略差。当为生存而正常化时，3HOH即使在较高剂量时也比X射线更有效。这一结果与之前用[~3H]胸腺嘧啶核苷得出的结果非常相似。[~3H]胸腺嘧啶核苷和3HOH结果的比较表明，氚衰变对并入DNA的放射性的转化效应可能是细胞毒性的一个重要因素，但不是转化的一个重要因素；两种类型的氚暴露对转化和诱变的有效性增强可能是由于在这些终点对氚β粒子具有较高的相对生物有效性。
Exponentially growing mouse BALB/3T3 cells seeded at low density were incubated with various concentrations of tritiated water (3HOH). A dose-dependent increase in the yield of transformants occurred in cells incubated for 100 h with 25 to 500 micrograms/ml of 3HOH. The dose-response curve rose linearly at low doses, with no evidence of a threshold or quadratic component. The transformation frequencies were similar when the same total dose of radiation was given over periods of 5 to 168 h, although survival was slightly lower with 5 h exposure compared with longer intervals. Acute X-ray exposure appeared to be more efficient in inducing transformation than protracted exposure to 3HOH at doses of 200-400 rad, but slightly less effective in the 25-100 rad range. When normalized for survival, 3HOH was more effective than X rays even at the higher doses. This result is very similar to previous findings with [3H]thymidine. A comparison of [3H]thymidine and 3HOH results suggest that the transmutational effect of tritium decay for radioactivity incorporated into DNA may be a significant factor in cytotoxicity but not in transformation; the enhanced effectiveness of both types of tritium exposure for transformation and mutagenesis may result from a higher relative biological effectiveness for the tritium beta particle for these end points.
DOI：
10.1016/0027-5107(83)90035-0
发表时间：
1983-11
期刊：
Mutation research
影响因子：
--
作者：
H. Liber;Peter K. LeMotte;John B. Little
通讯作者：
H. Liber;Peter K. LeMotte;John B. Little
氚化水低剂量率电离辐射对人淋巴母细胞的毒性和致突变性。
DOI：
10.1016/0165-1218(85)90052-7
发表时间：
1985
期刊：
Mutation research
影响因子：
--
作者：
Liber,HL;Ozaki,VH;Little,JB
通讯作者：
Little,JB
BALB/3T3 小鼠胚胎成纤维细胞中掺入放射性核素诱导恶性转化。
DOI：
10.1073/pnas.79.24.7763
发表时间：
1982
影响因子：
11.1
作者：
LeMotte,PK;Adelstein,SJ;Little,JB
通讯作者：
Little,JB