Jamali M, Trott K R
Department of Radiation Biology, St. Bartholomew's Hospital Medical College, London, UK.
Int J Radiat Biol. 1996 Mar;69(3):301-7. doi: 10.1080/095530096145850.
V79 Chinese hamster cells were irradiated with doses of 1-12 Gy 300 kV X-rays. Their colony-forming ability and the frequency of micronuclei in binucleate cells after treatment with cytochalasin B was determined at various times after irradiation. The frequency of micronuclei determined within the first 24 h after irradiation increased with doses up to 4 Gy and decreased as the dose increased further. Up to 4 Gy there was a close correlation between surviving fraction and the fraction of cells without micronuclei although the surviving fraction was 2-3 times lower than the fraction of cells without micronuclei. Six, 10 or 13 days after irradiation with either 9 or 12 Gy the plating efficiency and the frequency of micronuclei after cytokinesis block with cytochalasin B was determined in the irradiated, but surviving, cells. The delayed plating efficiency of irradiated cells was significantly decreased. The proportion of binucleated cells was in the normal range at 6-13 days after irradiation, indicating that the proliferative activity of irradiated but surviving cells was not depressed at that time. The micronucleus frequency, however, was significantly increased at all times after irradiation. There was little heterogeneity of plating efficiency and micronucleus frequency among 12 clones which had been isolated for irradiated cultures, 3 weeks after 12 Gy.
将V79中国仓鼠细胞用1 - 12 Gy的300 kV X射线进行照射。在照射后的不同时间，测定其集落形成能力以及用细胞松弛素B处理后双核细胞中的微核频率。照射后最初24小时内测定的微核频率在剂量达到4 Gy时随剂量增加而升高，剂量进一步增加时则降低。剂量达4 Gy时，存活分数与无微核细胞分数之间存在密切相关性，尽管存活分数比无微核细胞分数低2 - 3倍。在用9 Gy或12 Gy照射6、10或13天后，测定受照射但存活的细胞在细胞松弛素B诱导胞质分裂阻滞后的接种效率和微核频率。受照射细胞的延迟接种效率显著降低。照射后6 - 13天双核细胞比例处于正常范围，表明此时受照射但存活的细胞的增殖活性未受抑制。然而，照射后所有时间微核频率均显著升高。在12 Gy照射3周后从照射培养物中分离出的12个克隆之间，接种效率和微核频率几乎没有异质性。
