Integration of Water and Energy Balance in Hummingbirds

蜂鸟水和能量平衡的整合

• 批准号: 9514351
• 负责人: Carol Beuchat
• 金额: $ 9.95万
• 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: 1996
• 资助国家: 美国
• 起止时间: 1996-04-01 至 1998-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9514351&HistoricalAwards=false
• 关键词: Integration; Water; Energy; Balance; Hummingbirds

9514351 Beuchat Hummingbirds have the highest metabolic rate of any vertebrate, and they fuel this tremendous metabolism almost entirely with the sugar found in nectar. Supporting a high metabolic rate on liquid diet presents these birds with some special physiological problems. Most obviously, hummingbirds must consume tremendous quantities of nectar, up to five times the bird's own body mass per day! Then, the gastrointestinal tract must be able to extract, with great efficiency, the sugar and other nutrients in the nectar as it passes rapidly through the bird. The kidney must also be able to filter and excrete excess water to avoid dilution of body fluids. Finally, because concentrations of salts and minerals in nectar are typically low but are needed by the bird, the amounts excreted in the urine must be minimal. This research investigates the ways in which hummingbirds deal simultaneously with these extreme physiological challenges of fluid, electrolyte, and energy balance. The study focuses not only on understanding fundamental aspects of the physiology of the kidney and intestinal tract in hummingbirds, but also on how these organ systems play coordinated roles in the physiological maintenance of energy and osmotic homeostasis. The work is further extended by considering the integration of renal and intestinal function with hummingbird biology at the organismal level in a series of questions that address the interface of physiology with behavior, morphology, and ecology, and evolution. Much of what comparative physiology has contributed to our understanding of osmoregulation in terrestrial birds and mammals has been based upon studies of the ultimate concentrators, the desert rodents, and only a few species of birds. We know relatively little, by contrast, about the special osmoregulatory problems faced by birds and mammals for which the challenge is an exc ess of water rather than desiccation. This study is unusual in the breadth of its perspective and its simultaneous consideration of processes from the cellular level to that of the animal in the field. It is the first study to closely examine the osmoregulatory physiology of a bird or mammal that is a model organism for the study of diuresis in vertebrates.

小行星9514351 蜂鸟的新陈代谢率最高 的 任何脊椎动物，它们几乎完全用花蜜中的糖来补充这种巨大的新陈代谢。 以流质食物维持高代谢率会给这些鸟带来一些特殊的生理问题。最明显的是，蜂鸟必须消耗大量的花蜜，每天高达鸟自身体重的五倍！ 然后， 胃肠道必须能够在花蜜快速通过鸟类时高效地提取花蜜中的糖和其他营养物质。 肾脏还必须能够过滤和排泄多余的水，以避免稀释体液。 最后，由于花蜜中的盐和矿物质浓度通常很低，但鸟类需要，因此尿液中排泄的量必须最小。 这项研究调查了蜂鸟处理 同时 这些极端 液体、电解质和能量平衡的生理挑战。 该研究不仅关注蜂鸟肾脏和肠道生理学的基本方面，还关注这些器官系统如何在能量和渗透稳态的生理维持中发挥协调作用。 这项工作是进一步扩展考虑整合肾脏和肠道功能与蜂鸟生物学在有机体水平上的一系列问题，解决接口的生理学与行为，形态学，生态学和进化。 许多比较生理学的研究有助于我们理解陆生鸟类和哺乳动物的呼吸调节 是基于对终极浓缩者，沙漠啮齿动物和少数几种鸟类的研究。 相比之下，我们对鸟类和哺乳动物面临的特殊水分调节问题知之甚少，这些问题的挑战是水分过剩，而不是干燥。 这项研究是不寻常的，在其角度的广度和同时考虑的过程，从细胞水平的动物在该领域。 这是第一项仔细研究鸟类或哺乳动物利尿生理学的研究，鸟类或哺乳动物是研究脊椎动物利尿的模式生物。