EFFECT OF EXERCISE TRAINING/NUTRITIONAL SUPPORT DURING PROLONGED BED REST

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 持续暴露在微重力下会导致心血管和肌肉骨骼系统的适应性变化，这可能会损害正常功能，并导致大量疾病。例如，心脏萎缩、血容量不足或反射反应受限引起的心血管功能障碍可能会导致直立性低血压和晕厥。骨骼肌的废用性萎缩会降低工作能力，并可能导致肌肉损伤。骨脱矿会增加肾结石形成的风险，并可能降低骨骼强度，增加骨折的风险。在长时间的太空飞行后，骨吸收可能特别严重，但恢复情况不确定。以前在短期空间飞行任务中观察到的几乎所有变化在长时间飞行任务中可能会加剧，例如国际空间站上所需的任务或火星任务。然而，尽管进行了深入的研究，但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上，而忽略了系统之间的相互作用，阻止了针对单个宇航员的具体对策的开发和实际应用，这种对策可能对心脏、肌肉和骨骼有效。这项提议的全球目标是测试一种综合对策，该对策将有效地对抗心血管疾病、骨骼肌萎缩和骨骼脱矿化，并最终可以在国际空间站或火星任务中实际应用。

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.