Musculoskeletal Changes in Mice from 20-50 cGy of Simulated Galactic Cosmic Rays
Musculoskeletal Changes in Mice from 20-50 cGy of Simulated Galactic Cosmic Rays
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DOI：
10.1667/rr1509.1
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发表时间：
2009-07-01
影响因子：
3.4
通讯作者：
Bateman, Ted A.
中科院分区：
文献类型：
--
作者：
Bandstra, Eric R.;Thompson, Raymond W.;Bateman, Ted A.
在前往火星的使命中，宇航员将暴露在银河宇宙射线的复杂辐射混合物中。我们已经证明，暴露于与空间飞行有关的剂量为1和2戈伊的各类辐射会造成骨量损失。然而，尚未对空间辐射对骨骼肌的影响进行研究。为了评估模拟银河宇宙辐射对肌纤维面积和骨体积的影响，我们检查了一项研究中的小鼠，其中大脑暴露于准直铁离子辐射。准直器将带电次级粒子的复杂混合物传送到骨骼和肌肉组织，这是对空间辐射环境的低逼真度模拟。测量的未准直次级粒子的辐射剂量在肱骨近端为0.47戈伊，在肱三头肌中腹为0.24-0.31戈伊，在胫骨近端为0.18戈伊。与未辐照对照组相比，辐照小鼠肱骨近端的骨小梁体积分数较低，骨小梁厚度较低，皮质孔隙率较高，极惯性矩较低。胫骨的任何骨参数均无差异。照射组小鼠肱三头肌小直径纤维减少，含中央核的纤维增多。这些结果表明，在与火星探测使命相关的剂量和LET范围内，模拟银河宇宙射线对骨骼肌和骨骼系统有负面影响。肌肉重塑证据的存在突出了进一步研究的必要性。(C)2009年，辐射研究学会
On a mission to Mars, astronauts will be exposed to a complex mix of radiation from galactic cosmic rays. We have demonstrated a loss of bone mass from exposure to types of radiation relevant to space flight at doses of 1 and 2 Gy. The effects of space radiation on skeletal muscle, however, have not been investigated. To evaluate the effect of simulated galactic cosmic radiation on muscle fiber area and bone volume, we examined mice from a study in which brains were exposed to collimated iron-ion radiation. The collimator transmitted a complex mix of charged secondary particles to bone and muscle tissue that represented a low-fidelity simulation of the space radiation environment. Measured radiation doses of uncollimated secondary particles were 0.47 Gy at the proximal humerus, 0.24-0.31 Gy at the midbelly of the triceps brachii, and 0.18 Gy at the proximal tibia. Compared to nonirradiated controls, the proximal humerus of irradiated mice had a lower trabecular bone volume fraction, lower trabecular thickness, greater cortical porosity, and lower polar moment of inertia. The tibia showed no differences in any bone parameter. The triceps brachii of irradiated mice had fewer small-diameter fibers and more fibers containing central nuclei. These results demonstrate a negative effect on the skeletal muscle and bone systems of simulated galactic cosmic rays at a dose and LET range relevant to a Mars exploration mission. The presence of evidence of muscle remodeling highlights the need for further study. (C) 2009 by Radiation Research Society