Morales-Ramírez P, Mendiola-Cruz M T, Cruz-Vallejo V
Departmento de Genética, Instituto Nacional de Investigaciones Nucleares, México, DF México.
Mutagenesis. 1998 Mar;13(2):139-44. doi: 10.1093/mutage/13.2.139.
The in vivo effect of vitamin C or beta-carotene on sister chromatid exchange (SCE) radio-induction was determined in murine bone marrow cells sensitized by BrdU incorporation. Pre- or post-treatment with 100 mg/kg body wt vitamin C did not cause a significant reduction in SCE induced by the exposure to 0.63 Gy gamma-rays. Treatment with a double dose of vitamin C and with 0.45 Gy radiation did not cause a significant reduction in SCE frequency. However, due to the fact that vitamin C per se is capable of SCE induction, if an additive effect of radiation and vitamin C is considered, the expected frequency is higher than that observed. This implies that vitamin C could have a slight radioprotective activity. With regard to beta-carotene, it has been demonstrated that 50 mg/kg body wt causes a statistically significant increase per se, although pre- and post-treatment with the same dose has an additive effect on SCE frequency induced by 0.62 Gy radiation. This indicates that beta-carotene does not have radioprotective activity under the conditions used in the present study.
通过掺入BrdU使小鼠骨髓细胞致敏，从而测定维生素C或β-胡萝卜素对姐妹染色单体交换（SCE）辐射诱导的体内效应。以100mg/kg体重的维生素C进行预处理或后处理，并不会使暴露于0.63Gyγ射线所诱导的SCE显著减少。用双倍剂量的维生素C与0.45Gy辐射进行处理，也不会使SCE频率显著降低。然而，由于维生素C本身能够诱导SCE，若考虑辐射与维生素C的相加效应，预期频率会高于所观察到的频率。这意味着维生素C可能具有轻微的辐射防护活性。关于β-胡萝卜素，已证明50mg/kg体重的β-胡萝卜素本身会使SCE有统计学上的显著增加，尽管用相同剂量进行预处理和后处理对0.62Gy辐射诱导的SCE频率有相加效应。这表明在本研究使用的条件下，β-胡萝卜素不具有辐射防护活性。
