Acclimatization and adaptation to high altitude in newborn rats

新生大鼠对高海拔的驯化和适应

• 批准号: 261239-2009
• 负责人: Joseph, Vincent
• 金额: $ 1.68万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=504059
• 关键词: Acclimatization; adaptation; altitude; newborn; rats

At high altitude, the organism of most mammals responds with a series of adjustment that increases the transport of oxygen in the blood and its utilization by the cells. These responses include a gradual increase of ventilation, that develops over several days, due to a progressive increase of sensitivity of specialized cells sensing the decrease of blood oxygenation. Furthermore these responses varies with age (low in newborn and strong in adults), and this development is greatly influenced by environmental oxygen levels. Humans and animals raised under condition of low oxygen (such as occurring at high altitude) have a persistent and paradoxical defect in the ability of these cells to respond to low oxygen, hence their respiratory response is weaker than expected. It is one of our objective to further understand how this decrease of respiratory sensibility to low oxygen will prevent an adequate acclimatization to long-term hypoxia in adults. This question is of interest for the hundreds of millions of humans living at altitude ranging from 2500 to 4500 m worldwide. A secondary question of our research concerns the effect of low oxygen during postnatal development in rats permanently living at high altitude, in the capital-city of Bolivia, at 3600m above sea level. While responses to long-term exposure to low oxygen are well described in adults, studies in newborn are scarce, but are nonetheless critical to better understand how mammals, and men, may survive and develop into well-adapted adults at high altitude. We use rats raised at high altitude to define the contribution of high altitude hypoxia during postnatal development, a critical period for succesful reproduction. Genetic adaptation favors life at altitude, and some genetically adapted rodents are found at extremely high altitude in North America (4500 m). To understand the contribution of genetic background and during postnatal development at high altitude we will study development of respiratory control in these animals. These studies will expend our comprehension of the mechanisms underlying successful life at high altitude, a research area of long-lasting interest in physiology and respiratory biology.

在高海拔地区，大多数哺乳动物的生物都会通过一系列的调节做出反应，从而增加了血液中氧气的运输及其在细胞中的利用。这些反应包括通风的逐渐增加，这在几天内发展，这是由于专门细胞的敏感性逐渐增加，从而感知了血液氧合的降低。此外，这些反应随着年龄的增长而变化（新生儿较低，成年人在成年人中），并且这种发展受环境氧水平的极大影响。在低氧气状态下饲养的人和动物（例如在高海拔地区发生）在这些细胞对低氧反应的能力上具有持久和矛盾的缺陷，因此它们的呼吸反应较弱。我们的目标之一是进一步了解这种呼吸道降低对低氧的感觉如何阻止成人长期缺氧的适当适应。这个问题对于居住在全球2500至4500 m不等的数亿人类中是令人感兴趣的。我们研究的次要问题涉及在玻利维亚资本城市高海拔地区永久居住在海拔3600m海平面上的高海拔地区的大鼠中氧气中低氧的影响。尽管成人对长期暴露于低氧的反应在成年人中得到很好的描述，但在新生儿的研究很少，但是对于更好地了解哺乳动物和男性如何在高海拔地区生存并发展成为适应良好的成年人至关重要。我们使用在高海拔地区饲养的大鼠来定义产后发育期间高海拔缺氧的贡献，这是成功繁殖的关键时期。遗传适应有利于海拔高度的生命，在北美极高的海拔（4500 m）处发现了一些遗传适应的啮齿动物。为了了解遗传背景的贡献以及在高海拔地区产后发育期间，我们将研究这些动物呼吸道控制的发展。这些研究将花费我们对高空成功生活的机制的理解，这是一个对生理学和呼吸生物学兴趣持续兴趣的研究领域。