长期暴露于微重力对宇航员的状和皮质承重骨的影响
L Vico1, P Collet, A Guignandon
1Laboratoire de Biologie et Biochimie du Tissu Osseaux, INSERM E9901, GIP Exercice, Faculté de Médecine de St Etienne, France. vico@univ-st.etienne.fr
Lancet (London, England)
|May 23, 2000
概括
太空飞行会导致骨质损失,特别是骨,随着时间的推移,骨质损失会恶化,并在返回地球后持续存在. 个人反应各不相同,这表明需要预选和针对宇航员和骨质疏松症患者的有针对性的预防策略.
科学领域:
- 太空医学 太空医学
- 骨生理学 骨生理学
- 骨质疏松症的研究研究.
背景情况:
- 微重力被假定会导致骨质疏松症,因为减轻了承重能力.
- 关于微重力诱导的骨损失的具体性质和时间表的数据有限.
研究的目的:
- 为了研究宇宙飞行员在太空任务期间和之后骨矿物质密度 (BMD) 变化的精确性质和时间过程.
- 评估微重力对不同骨部位 (半径与骨) 和骨类型 (状与皮质) 的影响.
主要方法:
- 骨矿物质密度 (BMD) 测量了15名宇航员的远半径和骨.
- 测量是在类似持续时间的太空任务之前,期间 (1,2,或6个月) 和之后进行的.
- 包括在承重部位 (大骨) 和非承重部位 (半径) 的切骨和皮层骨的分析.
主要成果:
- 没有观察到半径骨矿物质密度 (BMD) 的显著变化.
- 承重性骨显示显著无效的BMD损失,从一个月内开始,随着任务持续时间的增加而恶化.
- 在2个月后注意到皮质骨损失,在较长的任务中,取消性骨损失比皮质骨损失更明显.
- 骨损失在恢复期间持续存在,这表明恢复时间比任务持续时间更长.
- 个体骨反应显示出显著的变化.
结论:
- 太空飞行引起的骨损失是一种适应性过程,即使在进行体育训练时,在返回地球时也可能变得病态.
- 骨反应的显著个体间差异需要船员预选.
- 有针对性的预防和治疗策略对于太空飞行和地球上的骨质疏松症管理至关重要.
相关概念视频
02:59Biological Effects of Radiation
All radioactive nuclides emit high-energy particles or electromagnetic waves. When this radiation encounters living cells, it can cause heating, break chemical bonds, or ionize molecules. The most serious biological damage results when these radioactive emissions fragment or ionize molecules. For example, α and β particles emitted from nuclear decay reactions possess much higher energies than ordinary chemical bond energies. When these particles strike and penetrate matter, they produce ions...
01:19The Effect of Aging on Tissues
Several body functions deteriorate with age. The external signs of aging are easily identifiable. For example, the skin becomes dry, less elastic, and thins out, forming wrinkles. The skin of the face begins to appear looser due to a decrease in the levels of elastic and collagen fibers in the connective tissue. Additionally, melanin production in the hair follicle decreases with age, resulting in gray hair. Moreover, the senses of sight and hearing decline, so glasses and hearing aids may...
01:29Blood and Nerve Supply to the Bones
Bones are dynamic organs that require a rich supply of oxygen and nutrients. Around 5% to 10% of the cardiac output supplies blood to the bones. A typical long bone has three main sources: the nutrient artery, the metaphyseal and epiphyseal arteries, and the periosteal arteries.
Nutrient Artery
The nutrient artery is the main blood vessel that enters the diaphysis via the nutrient foramen. While most long bones have only one nutrient foramen, large bones, such as the femur, may have two. This...
Nutrient Artery
The nutrient artery is the main blood vessel that enters the diaphysis via the nutrient foramen. While most long bones have only one nutrient foramen, large bones, such as the femur, may have two. This...
01:29Bone Disorders
Aging and its effect on bone remodeling is the most common cause of bone disorders. In young and healthy people, bone deposition and resorption happen at an equal rate to maintain optimal bone health.
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...