Harada K, Sugahara T, Ohnishi T, Ozaki Y, Obiya Y, Miki S, Miki T, Imamura M, Kobayashi Y, Watanabe H, Akashi M, Furusawa Y, Mizuma N, Yamanaka H, Ohashi E, Yamaoka C, Yajima M, Fukui M, Nakano T, Takahashi S, Amano T, Sekikawa K, Yanagawa K, Nagaoka S
Oji-cho, Kitakatsuragi-gun, Nara 636-0002, Japan.
Int J Mol Med. 1998 May;1(5):817-22. doi: 10.3892/ijmm.1.5.817.
We participated in a space experiment, part of the National Space Development Agency of Japan (NASDA) Phase I Space Radiation Environment Measurement Program, conducted during the National Aeronautics and Space Administration (NASA) Shuttle/Mir Mission No. 6 (S/MM-6) project. The aim of our study was to investigate the effects of microgravity on the DNA repair processes of living organisms in the <Realtime Radiation Monitoring Device III (RRMD III)> in orbit. Heavy ion beam radiation- or ç-irradiation-damaged biological samples of Escherichia coli and the radioresistant bacterium Deinococcus radiodurans were prepared and placed in a biospecimen box, which was loaded into the RRMD III sensor unit of the Space Shuttle. Two identical sets of samples were left in the Spacehab's Payload Processing Facility (SPPF) in Florida, USA, as a control. (flight No. STS-84) was launched from NASA John F. Kennedy Space Center (KSC) in Florida, USA, on May 15, 1997. The mission duration was 9.22 days. An astronaut activated the biological samples in the biospecimen box in the Spacehab during orbit in order to start repair of the DNA damaged by heavy ion beams or ç-irradiation and the samples were incubated for 19 h 35 min at about 22ûC, the cabin temperature. The control specimens in the SPPF were subjected to the same treatment under terrestrial gravity. After returned to earth, we investigated cell recovery by comparing the repair of the radiation-damaged DNA of E. coli and D. radiodurans in the microgravity environment in space with that on Earth. The results indicated that the DNA repair process of E. coli, but not of D. radiodurans, cells was inhibited in a microgravity environment.
我们参与了一项太空实验，该实验是日本国家太空开发局（NASDA）第一阶段太空辐射环境测量计划的一部分，在国家航空航天局（NASA）航天飞机/和平号空间站任务6（S/MM - 6）项目期间进行。我们研究的目的是在轨道上的<实时辐射监测装置III（RRMD III）>中，研究微重力对生物体DNA修复过程的影响。制备了重离子束辐射或γ射线辐照损伤的大肠杆菌和耐辐射细菌耐辐射球菌的生物样本，并将其置于生物样本盒中，该生物样本盒被装入航天飞机的RRMD III传感器单元。两套相同的样本留在美国佛罗里达州太空实验室的有效载荷处理设施（SPPF）中作为对照。（飞行编号STS - 84）于1997年5月15日从美国佛罗里达州NASA约翰·F·肯尼迪航天中心（KSC）发射。任务持续时间为9.22天。一名宇航员在轨道运行期间激活了太空实验室中生物样本盒内的生物样本，以启动对重离子束或γ射线辐照损伤的DNA的修复，样本在约22℃（舱内温度）下孵育19小时35分钟。SPPF中的对照样本在地球重力下接受相同处理。返回地球后，我们通过比较太空微重力环境下和地球上大肠杆菌及耐辐射球菌辐射损伤DNA的修复情况来研究细胞恢复。结果表明，在微重力环境下，大肠杆菌细胞的DNA修复过程受到抑制，而耐辐射球菌细胞的DNA修复过程未受抑制。
