Integration of Water and Energy Balance in Hummingbirds

蜂鸟水和能量平衡的整合

• 批准号: 9307024
• 负责人: Carol Beuchat
• 金额: $ 23.8万
• 依托单位: San Diego State University Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-09-01 至 1998-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9307024&HistoricalAwards=false
• 关键词: Integration; Water; Energy; Balance; Hummingbirds

9307024 Beuchat Hummingbirds subsist almost entirely on a liquid diet composed of floral nectar, and when energy demands are high they can consume more than three times their own body mass in fluid per day. At the same time, however, the hummingbird's high metabolism requires efficient extraction of nutrients and electrolytes from a dilute food source that is passing rapidly through the gastrointestinal tract for efficient nutrient extraction, electrolyte conservation, and rapid elimination of water. For a hummingbird to simultaneously balance energy, water, and ion fluxes is a major challenge that raises fundamental questions about hummingbird morphology and physiology. This study proposes to address a central problem: In what ways and by what mechanisms do the kidney and gastrointestinal tract of hummingbird contribute to water and ion homeostasis while at the same time allowing maximum efficiency of energy acquisition? Using isotopically-labeled markers in artificial nectar, I can determine the fraction of ingested fluid that is absorbed by the intestine and the capacity of the kidney to eliminate excess water without depleting the body of electrolytes. The efficiency of energy and nutrient extraction are determined under conditions that influence the hummingbird's energy requirements, its electrolyte balance, and the quality of its diet. Together, these studies will provide information about the unique adaptations that allow hummingbirds to specialize on a liquid diet. ***

小行星9307024 蜂鸟几乎完全依靠花蜜组成的流质食物生存，当能量需求很高时，它们每天可以消耗超过自身体重三倍的液体。 然而，与此同时，蜂鸟的高代谢需要从快速通过胃肠道的稀释食物源中有效提取营养素和电解质，以有效提取营养素，保存电解质并快速消除水分。 对于蜂鸟来说，同时平衡能量、水和离子流是一个重大挑战，它提出了关于蜂鸟形态学和生理学的基本问题。 本研究提出解决一个核心问题： 蜂鸟的肾脏和胃肠道以何种方式和机制提供水分 和离子稳态，同时允许能量获取的最大效率？ 使用人造花蜜中的同位素标记物，我可以确定肠道吸收的摄入液体的比例以及肾脏消除多余水分而不消耗体内电解质的能力。 能量和营养提取的效率是在影响蜂鸟的能量需求、电解质平衡和饮食质量的条件下确定的。 总之，这些研究将提供有关蜂鸟独特适应性的信息，这些适应性使蜂鸟能够专注于液体饮食。 ***