Osmak M, Horvat D
Department of Experimental Biology and Medicine, Ruder Bosković Institute, Zagreb, Croatia.
Mutat Res. 1992 Aug;282(4):259-63. doi: 10.1016/0165-7992(92)90132-2.
Chinese hamster V79 cells were irradiated daily with 0.3 Gy of gamma-rays 5 times per week for 12 weeks (total 18 Gy). These cells were challenged with an additional dose of 15. Gy gamma-rays or treated with 5 micrograms/ml of mitomycin C (MMC) for 2 h. In spite of the high total accumulated dose of gamma-rays, the number of chromosomal aberrations and sister-chromatid exchanges (SCEs) did not significantly increase in the preirradiated cells, as compared to control cells. If preirradiated cells were challenged with an additional 1.5 Gy of gamma-rays, an insignificant decrease in the yield of chromatid aberrations was observed. In contrast, preirradiated cells became significantly more resistant to the induction of chromosomal damage when challenged with mitomycin C. Our results suggest that multiple fractions of gamma-rays can induce the adaptive response to mitomycin C in preirradiated cells.
中国仓鼠V79细胞每周5次，每次接受0.3 Gy的γ射线照射，持续12周（总计18 Gy）。这些细胞再接受额外15 Gy的γ射线照射，或用5微克/毫升的丝裂霉素C（MMC）处理2小时。尽管γ射线的总累积剂量很高，但与对照细胞相比，预照射细胞中的染色体畸变和姐妹染色单体交换（SCE）数量并未显著增加。如果预照射细胞再接受额外1.5 Gy的γ射线照射，观察到染色单体畸变率有不显著的下降。相反，当用丝裂霉素C处理时，预照射细胞对染色体损伤诱导的抗性显著增强。我们的结果表明，多次分割的γ射线可诱导预照射细胞对丝裂霉素C产生适应性反应。
