EFFECT OF EXERCISE TRAINING/NUTRITIONAL SUPPORT DURING PROLONGED BED REST

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 中心，不一定是研究者的机构。 持续暴露在微重力环境下会导致心血管和肌肉骨骼系统发生适应性变化，从而可能损害正常功能并导致严重的发病率。 例如，由心脏萎缩、血容量不足或反射反应受限引起的心血管失调可能导致直立性低血压和晕厥。 骨骼肌废用性萎缩会降低工作能力，并可能导致肌肉损伤。 骨脱矿增加肾结石形成的风险，并可能降低骨强度，增加骨折的风险。在长时间的空间飞行后，骨吸收可能特别严重，恢复不确定。 实际上，以前在短期空间飞行任务中观察到的所有变化在长期飞行任务中可能会加剧，例如国际空间站或火星使命所需的变化。 然而，尽管进行了深入的研究，每个系统的最佳对策尚未确定。 更重要的是，以前的工作主要集中在一个器官系统的时间，忽略了系统之间的相互作用，并防止开发和实际应用的具体对策，为个人宇航员，可能是有效的心脏，肌肉和骨骼。 这项建议的全球目标是测试一种综合对策，这种对策将有效地防止心血管失调、骨骼肌萎缩和骨脱矿，并最终实际应用于国际空间站或火星使命。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Sustained exposure to microgravity leads to adaptive changes in the cardiovascular and musculoskeletal systems that may impair normal function and result in substantial morbidity. For example cardiovascular deconditioning caused by cardiac atrophy, hypovolemia, or limited reflex responsiveness may lead to orthostatic hypotension and syncope. Disuse atrophy of skeleltal muscle will diminish work capacity and may lead to muscle injury. Bone demineralization increases the risk of kidney stone formation, and may reduce bone strength increasing the risk of fracture. Bone resorption may be particularly severe after long duration space flight with uncertain recovery. Virtually all the changes previously observed in short duration space missions may be exacerbated during long duration missions, such as those required aboard the International Space Station, or a mission to Mars. However despite in depth study, the optimal countermeasure for each system has not yet been defined. More importantly, previous work has focused primarily on one organ system at a time, ignoring the interaction among systems, and preventing the development and practical application of a specific countermeasure for an individual astronaut that might be effective for the heart, muscles and bones. The global objective of this proposal is to test an integrated countermeasure that will be effective against cardiovcascular deconditioning, skeletal muscle atrophy, and bone demineralizqtion, and that ultimately can be applied practically aboard the International Space Station or a mission to Mars.