Zhang H, Zheng R L, Wang R Y, Wei Z Q, Li W J, Gao Q X, Chen W Q, Wang Z H, Han G W, Liang J P
Department of Application of Heavy Ions, Institute of Modern Physics, The Chinese Academy of Sciences, Lanzhou, People's Republic of China.
Mutat Res. 1998 Feb 26;398(1-2):27-31. doi: 10.1016/s0027-5107(97)00236-4.
The testes of Kun-Ming strain mice were radiated with different doses of 12C6+ ion or 60Co gamma-ray. Chromosomal aberrations induced in spermatogonia and spermatocytes were analyzed by the air-drying method. The relative biological effectiveness (RBE) of 12C6+ ion was calculated with respect to 60Co gamma-ray for the induction of chromosomal aberrations. The 12C6+ ion and 60Co gamma-ray dose-response relationships for chromosomal aberrations were plotted by linear quadratic models. The results showed that there was an increase in frequency of chromosomal aberrations in all the treated groups compared to controls. The RBE values were 1.67 for aberrations of spermatogonia and 1.66 for aberrations of spermatocytes for a dose of 2.0 Gy. Moreover, a different distribution of the various types of aberrations has been found for 12C6+ ion and 60Co gamma-ray irradiations. The dose-response relationships for 12C6+ ion and 60Co gamma-ray exhibited negative curvature in both spermatogonia and spermatocytes groups: the frequencies of aberrations increased sharply at low doses and exhibited less sharp increases for higher doses, which may be related to an interaction between the chromosomal damage and a block in cell cycle. Our results may provide useful information for the assessment of genetic risks of humans exposed to heavy ions.
用不同剂量的(^{12}C^{6 + })离子或(^{60}Co)γ射线辐照昆明种小鼠的睾丸。采用空气干燥法分析精原细胞和精母细胞中诱导产生的染色体畸变。计算了(^{12}C^{6 + })离子相对于(^{60}Co)γ射线诱导染色体畸变的相对生物效应（RBE）。用线性二次模型绘制了(^{12}C^{6 + })离子和(^{60}Co)γ射线诱导染色体畸变的剂量-反应关系。结果表明，与对照组相比，所有处理组的染色体畸变频率均增加。对于(2.0 Gy)的剂量，精原细胞畸变的RBE值为(1.67)，精母细胞畸变的RBE值为(1.66)。此外，已发现(^{12}C^{6 + })离子和(^{60}Co)γ射线辐照导致的各类畸变分布不同。(^{12}C^{6 + })离子和(^{60}Co)γ射线在精原细胞和精母细胞组中的剂量-反应关系均呈现负曲率：畸变频率在低剂量时急剧增加，在高剂量时增加幅度较小，这可能与染色体损伤和细胞周期阻滞之间的相互作用有关。我们的结果可能为评估人类暴露于重离子的遗传风险提供有用信息。
