低剂量碳离子诱导的哺乳动物细胞适应性反应的研究

STUDY ON THE ADAPTIVE RESPONSE OF MAMMALIAN CELLS INDUCED BY LOW DOSE RADIATION OF CARBON IONS

研究了高 ＬＥＴ的碳离子对 Ｖ７９细胞和 Ｂ１６细胞的低剂量效应。细胞经 ０．０２Ｇｙ和０．０５Ｇｙ的诱导剂量处理后，继续培养 ４ ｈ，再经 １Ｇｙ攻击剂量处理，从存活率和微核率两方面研究了细胞的适应性反应。结果表明：经 ０．０２Ｇｙ诱导剂量处理以后，两种细胞在存活率和微核率方面分别表现为明显的提高和下降，相反，经 ０．０５Ｇｙ诱导剂量处理以后，细胞在存活率方面没有表现出有统计学意义的差别，在微核率方面表现出协同损伤的趋势。因此，０．０２Ｇｙ的高ＬＥＴ射线辐照能诱导体外培养细胞的适应性反应， ０．０５Ｇｙ则不能。同时，微核率与存活率呈线性负相关，低剂量如 ０．０２Ｇｙ预辐照能使细胞微核率降低，存活率提高。

The effects of high LET carbon ions irradiation with low dose on V_79 Chinese hamster cells and B_16 melanoma cells were investigated in this paper. The cells were treated with inducing doses of 0.02Gy and 0.05Gy first, and then with challenge dose of 1Gy after additional culture of 4h. The adaptive responses including survival fraction and micronucleus frequency were studied. Our results showed that when the inducing dose was chosen as 0.02Gy, there were marked increase of surviving fraction and decrease of micronucleus frequency in both cell lines. On the contrary, when the inducing dose was chosen as 0.05Gy, there was no statistical change of surviving fraction, furthermore, the micronucleus frequency increased a little. This meant that high LET radiation of 0.02Gy could induce the adaptive response of cultured cells while 0.05Gy can not. Meanwhile, there was a good linear relationship between micronucleus frequency and surviving fraction, cells pre-exposed to low dose such as 0.02Gy had low micronucleus frequency and high surviving fraction.