The Integrative Aspects of Fluid and Electrolyte Balance in Birds

鸟类体液和电解质平衡的综合方面

• 批准号: 8919622
• 负责人: Eldon Braun
• 金额: $ 26.6万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-02-15 至 1993-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8919622&HistoricalAwards=false
• 关键词: Integrative; Aspects; Fluid; Electrolyte; Balance

The proposed research is to study how two organ systems are integrated to regulate fluid and electrolytes in birds. In mammals the output of the kidneys (the urine) is conveyed to a storage organ, the urinary bladders. This urine, once it leaves the kidneys is not modified. Birds do not have urinary bladders to store the urine. Instead the urine is conveyed by the ureters to the terminal segment of the gastrointestinal tract (the cloaca). The urine does not remain here. It is carried into the colon by a reverse action of the colonic muscle layers. In the colon, the urine formed by the kidneys can be modified. How the kidneys and colon of birds are integrated into a unit that functions in a concerted fashion to maintain the fluid and electrolyte balance is not understood. The research outlined in this proposal is directed toward answering some aspects of this basic question. A second aspect of the proposal deals with the chemistry of nitrogen excretion in birds. Mammals (including humans) excrete the majority of waste nitrogen as urea, a very water soluble compound. Birds excrete waste nitrogen in the form of uric acid, a very water insoluble compound. Excreting nitrogen as uric acid could lead to problems of kidney stone formation as it does in humans. However, birds excrete large amounts of uric acid without forming kidney stones. How this occurs is not understood. A portion of this grant proposal deals with research that is directed toward answering this very fundamental question.

拟议的研究旨在研究两个器官系统如何整合来调节鸟类的液体和电解质。 在哺乳动物中，肾脏的排出物（尿液）被输送到储存器官，即膀胱。 这种尿液一旦离开肾脏就不会被改变。 鸟类没有储存尿液的膀胱。 相反，尿液通过输尿管输送到胃肠道的末端部分（泄殖腔）。 尿液不会留在这里。 它通过结肠肌肉层的反向作用被带入结肠。 在结肠中，肾脏形成的尿液可以被改变。 鸟类的肾脏和结肠如何整合成一个以协调一致的方式发挥作用以维持液体和电解质平衡的单元尚不清楚。 本提案中概述的研究旨在回答这个基本问题的某些方面。 该提案的第二个方面涉及鸟类氮排泄的化学性质。 哺乳动物（包括人类）将大部分废氮以尿素的形式排出，尿素是一种极易溶于水的化合物。 鸟类以尿酸的形式排出废氮，尿酸是一种非常不溶于水的化合物。 以尿酸形式排出氮可能会导致肾结石形成的问题，就像人类一样。 然而，鸟类排出大量尿酸，但不会形成肾结石。 这是如何发生的尚不清楚。 该拨款提案的一部分涉及旨在回答这个非常基本问题的研究。