Pushing the Envelope of Hypoxemia: Blood Oxygen Depletion in Elephant Seals

突破低氧血症的极限：象海豹的血氧耗尽

• 批准号: 0641801
• 负责人: Paul Ponganis
• 金额: $ 25.05万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-15 至 2011-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0641801&HistoricalAwards=false
• 关键词: Pushing; Envelope; Hypoxemia; Blood; Oxygen

The elephant seal is the premier diver among seals and sea lions; it routinely holds its breath for 20 minutes as it dives to depths greater than 400 meters. This project investigates the physiology that allows this seal to make such remarkable dives. In particular, it is hypothesized that these seals can withstand extremely low levels of oxygen, and that this allows them to almost completely deplete their blood of oxygen during diving. Such extreme tolerance to low levels of oxygen is beyond that found in any mammal, and well below the oxygen levels found in humans attempting to climb Mt Everest without supplemental oxygen. In order to examine this hypothesis, seals will be equipped with backpack oxygen recorders which will provide a profile of the oxygen pressure in the blood as the seal dives. It is expected that the oxygen levels in the blood will be near zero by the end of the dive, and that it is this nearly complete utilization of the blood oxygen which allows elephant seals to dive as well as they do. This study will establish the physiological limits to which these seals push themselves. This is relevant to their ability to successfully find prey underwater and to their overall ecology in an environment that may be changing due to over fishing and global warming. In addition, the mechanisms which allow the seals to tolerate such low oxygen levels may be relevant to our understanding and treatment of various pathological states in humans in which tissues are exposed to inadequate oxygen or blood flow (hypoxemia or ischemia). Lastly, in addition to involving students directly in the research, this project will develop an educational website which will provide behavioral and physiological information on deep-diving whales, seals, penguins, and sea turtles.

大象印章是海豹和海狮之间的主要潜水员。它通常会屏住呼吸20分钟，因为它潜入大于400米的深度。 该项目调查了使该密封能够进行如此出色的潜水的生理学。特别是，假设这些密封可以承受极低水平的氧气，这使他们几乎可以在潜水过程中几乎完全耗尽氧气的血液。 对低水平的氧气的这种极端耐受性超出了任何哺乳动物中发现的，远低于试图爬上珠穆朗玛峰而没有补充氧气的人类中发现的氧气水平。 为了审查这一假设，密封件将配备背包氧气记录仪，这些记录器将在密封潜水时提供血液中氧气压力的特征。 预计到潜水结束时，血液中的氧气水平将接近零，并且几乎完全利用了血氧，从而使大象密封能够像它们一样潜水。 这项研究将建立这些密封仪推动的生理限制。 这与他们成功找到水下猎物的能力以及在由于过度捕鱼和全球变暖可能发生变化的环境中与其整体生态学有关。 此外，允许密封剂耐受这种低氧水平的机制可能与我们对人类中各种病理状态的理解和治疗有关，在该病理中，组织暴露于氧气或血液流量不足（低氧血症或缺血）。 最后，除了直接参与研究之外，该项目还将开发一个教育网站，该网站将提供有关深水鲸，海豹，企鹅和海龟的行为和生理信息。