Institute of Biophysics SB RAS, Federal Research Center 'Krasnoyarsk Science Center SB RAS', 50/50 Akademgorodok, Krasnoyarsk, 660036, Russia; Siberian Federal University, 79 Svobodny Prospect, Krasnoyarsk, 660041, Russia.
Institute of Biophysics SB RAS, Federal Research Center 'Krasnoyarsk Science Center SB RAS', 50/50 Akademgorodok, Krasnoyarsk, 660036, Russia; Krasnoyarsk State Agrarian University, 90 Mira Prospect, Krasnoyarsk, 660049, Russia.
J Environ Radioact. 2017 Apr;169-170:64-69. doi: 10.1016/j.jenvrad.2017.01.002. Epub 2017 Jan 10.
The study addresses biological effects of low-dose gamma-radiation. Radioactive Cs-containing particles were used as model sources of gamma-radiation. Luminous marine bacterium Photobacterium phosphoreum was used as a bioassay with the bioluminescent intensity as the physiological parameter tested. To investigate the sensitivity of the bacteria to the low-dose gamma-radiation exposure (≤250 mGy), the irradiation conditions were varied as follows: bioluminescence intensity was measured at 5, 10, and 20°С for 175, 100, and 47 h, respectively, at different dose rates (up to 4100 μGy/h). There was no noticeable effect of gamma-radiation at 5 and 10°С, while the 20°С exposure revealed authentic bioluminescence inhibition. The 20°С results of gamma-radiation exposure were compared to those for low-dose alpha- and beta-radiation exposures studied previously under comparable experimental conditions. In contrast to ionizing radiation of alpha and beta types, gamma-emission did not initiate bacterial bioluminescence activation (adaptive response). As with alpha- and beta-radiation, gamma-emission did not demonstrate monotonic dose-effect dependencies; the bioluminescence inhibition efficiency was found to be related to the exposure time, while no dose rate dependence was found. The sequence analysis of 16S ribosomal RNA gene did not reveal a mutagenic effect of low-dose gamma radiation. The exposure time that caused 50% bioluminescence inhibition was suggested as a test parameter for radiotoxicity evaluation under conditions of chronic low-dose gamma irradiation.
该研究探讨了低剂量伽马辐射的生物学效应。放射性 Cs 含颗粒被用作伽马辐射的模型源。发光海洋细菌 Photobacterium phosphoreum 被用作生物测定，以生物发光强度作为测试的生理参数。为了研究细菌对低剂量伽马辐射暴露（≤250 mGy）的敏感性，如下调整了照射条件：在不同的剂量率（高达 4100 μGy/h）下，分别在 5、10 和 20°C 下测量生物发光强度 175、100 和 47 h。在 5 和 10°C 下，伽马辐射没有明显的影响，而 20°C 的暴露则显示出真实的生物发光抑制。将 20°C 下的伽马辐射暴露结果与先前在类似实验条件下研究的低剂量 α 和 β 辐射暴露结果进行了比较。与 α 和 β 类型的电离辐射不同，伽马发射没有引发细菌生物发光的激活（适应性反应）。与 α 和 β 辐射一样，伽马发射没有表现出单调的剂量-效应依赖性；生物发光抑制效率与暴露时间有关，而没有发现剂量率依赖性。16S 核糖体 RNA 基因的序列分析没有显示低剂量伽马辐射的诱变效应。建议将导致 50%生物发光抑制的暴露时间作为在慢性低剂量伽马辐射条件下进行放射性毒性评估的测试参数。
