Faculty of Health Science, Juntendo University, Tokyo, 113-0034, Japan.
Faculty of Food and Health Sciences, Showa Women's University, Tokyo, 154-8533, Japan.
Sci Rep. 2023 Aug 1;13(1):12479. doi: 10.1038/s41598-023-38990-1.
The impact of deep space cosmic rays on food resources is as important as the risks of cosmic rays to the human body. This study demonstrates the potential for neutrons as secondary radiation in deep space spacecraft to cause meat activation and oxidative modification of proteins and lipids. We conducted a series of experiments such as the neutron irradiation experiment, the radioactivation analysis and the biochemical analysis. Neutrons with energies from 1 to 5 MeV with doses from 0.01 Gy to 4 Gy were irradiated by the RIKEN accelerated-driven neutron source (RANS). Radioactive nuclei, Na, K, and Cl, were detected in the neutron-irradiated meat. The modification products of the proteins by oxidative nitration, 6-nitrotryptophan (6NOTrp), and by a lipid peroxidation, 4-hydroxy-2-nonenal (4-HNE), were detected in several proteins with neutron dose dependent. The proteome analysis showed that many oxidative modifications were detected in actin and myosin which are major proteins of myofibrils. This study is of crucial importance not only as risk factors for human space exploration, but also as fundamental effects of radiation on the components of the human body.
深空宇宙射线对食物资源的影响与宇宙射线对人体的风险同样重要。本研究表明，在深空航天器中，中子作为次级辐射，可能会导致肉类中的蛋白质和脂质发生激活和氧化修饰。我们进行了一系列实验，如中子辐照实验、放射性分析和生化分析。利用 RIKEN 加速驱动中子源（RANS），用能量为 1 到 5 MeV、剂量为 0.01 到 4 Gy 的中子对肉进行辐照。在中子辐照的肉中检测到放射性核素 Na、K 和 Cl。在几种蛋白质中，检测到蛋白质的氧化硝化修饰产物 6-硝基色氨酸（6NOTrp）和脂质过氧化产物 4-羟基-2-壬烯醛（4-HNE），这些修饰产物与中子剂量呈依赖性关系。蛋白质组分析表明，在肌动蛋白和肌球蛋白中检测到许多氧化修饰，肌动蛋白和肌球蛋白是肌原纤维的主要蛋白质。这项研究不仅对人类太空探索的风险因素具有重要意义，而且对辐射对人体成分的基本影响也具有重要意义。
