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目的探讨生理性周期动态力学载荷与过载对微重力致骨质疏松的作用及影响,为宇航员长时间外太空活动发生的相关骨科疾病寻找一种简便的预防或治疗方案。方法利用尾吊的方法模拟太空微重力环境,建立小鼠骨质疏松模型。32只C57BL/6J正常小鼠随机分为正常组、尾吊组、生理性载荷组和过载组;尾吊的同时对两施加力学载荷组小鼠左侧胫骨进行周期性动态力学加载。实验4周后对比分析各组小鼠后肢胫骨力学性能、骨小梁微观参数、生化指标以及成骨相关基因表达结果。结果与正常组相比,尾吊组小鼠胫骨松质骨大量流失,胫骨生物力学性能明显降低,骨微观结构严重破坏、成骨活性显著减弱。生理性载荷可使骨力学性能及骨小梁微观结构有明显的改善,成骨活性增强、相关基因表达显著上调(P<0.05)。过载也能改善微重力下骨质疏松的状况,但改善效果不明显(P>0.05)。结论尾吊可成功模拟微重力环境,复制骨质疏松模型;生理性载荷可有效对抗微重力致骨质疏松的发生与发展;过载也能使得微重力所致骨质疏松有所改善,但是结果与尾吊组相比没有显著性差异。
OBJECTIVE: To investigate the effect and impact of dynamic periodic dynamic mechanical loading and overload on osteoporosis caused by microgravity, and to find a simple prophylactic or therapeutic plan for the related orthopedic diseases associated with astronauts’ long time space activities. Methods Tail hanging method was used to simulate the space micro-gravity environment and a mouse osteoporosis model was established. Twenty-two C57BL / 6J normal mice were randomly divided into normal group, tail suspension group, physiological load group and overload group. Tail suspension was performed simultaneously on the left tibia of rats subjected to mechanical loading. Four weeks after the experiment, the tibial mechanical properties, trabecular bone microscopic parameters, biochemical indexes and osteogenesis-related gene expression of mice in each group were compared. Results Compared with the normal group, the loss of tibial cancellous bone in the tail suspension group was significantly reduced, the biomechanical properties of the tibia were significantly reduced, the microstructure of the bone was severely damaged and the osteogenic activity was significantly weakened. Physiological loading could significantly improve the bone mechanical properties and the trabecular structure. The osteogenic activity increased and the expression of related genes was significantly up-regulated (P <0.05). Overloading can also improve the status of osteoporosis under microgravity, but the improvement effect is not obvious (P> 0.05). Conclusion The tail-hanging can successfully simulate the micro-gravity environment and replicate the osteoporosis model. The physiological load can effectively resist the occurrence and development of microgravity-induced osteoporosis. Overloading can also improve the osteoporosis caused by microgravity. However, the results There was no significant difference compared with tail suspension group.