DISSERTATION RESEARCH: Effects of Angiotensin II and Dehydration on Regional Blood Flows in a Terrestrial Amphibian

论文研究：血管紧张素 II 和脱水对陆生两栖动物局部血流的影响

• 批准号: 9902257
• 负责人: Stephen Warburton
• 金额: $ 0.45万
• 依托单位: New Mexico State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2001-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9902257&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Effects; Angiotensin; II

Animals lose body water that must be replenished to avoid dehydration or even death. Unlike humans, amphibians, e.g. frogs and toads, have very thin skin and are susceptible to high rates of water loss. Additionally, amphibians do not drink; instead they absord water through the skin of their belly. Despite these differences, the same hormone, or chemical, in both humans and amphibians is involved in stimulating thirst. This hormone, angiotensin II, is formed when an animal becomes dehydrated. Angiotensin II is thus closely linked to thirst behavior. Angiotensin II is thus closely linked to thirst behavior. Angiotensin II has a second effect: it decreases blood flow by constricting blood vessels. Absorption of water across the skin is assumed to require increased blood flow, yet angiotensin II is known to decrease blood flow. Thus, this hormone may stimulate conflicting responses in amphibians. In amphibians as well as in humans, very little is know regarding the site where angiotensin II changes blood flows in terrestrial amphibians. Specifically, blood flow to tissues involved in water loss and water gain will be measured before and after angiotensin II injections and blockade of angiotensin II effects. The goal is to determine how an animal adapts to these apparantly conflicting effects of a single hormone. This research will add to the PIs understanding of the important role angiotensinII has played in the evolution of dehydration and rehydration behavior in animals

动物会失去体内的水分，必须补充这些水分才能避免脱水甚至死亡。与人类不同的是，两栖动物，如青蛙和蟾蜍，皮肤非常薄，很容易失水。此外，两栖动物不喝水，而是通过腹部的皮肤吸收水分。尽管有这些不同之处，但人类和两栖动物体内的相同荷尔蒙或化学物质与刺激口渴有关。这种荷尔蒙，血管紧张素II，是在动物脱水时形成的。因此，血管紧张素II与口渴行为密切相关。因此，血管紧张素II与口渴行为密切相关。血管紧张素II还有第二种作用：它通过收缩血管来减少血流量。皮肤对水的吸收被认为需要增加血液流量，但血管紧张素II已知会减少血液流量。因此，这种荷尔蒙可能会刺激两栖动物相互矛盾的反应。在两栖动物和人类中，关于血管紧张素II改变陆地两栖动物血液流动的部位知之甚少。具体地说，在血管紧张素II注射和阻断血管紧张素II效应之前和之后，将测量涉及失水和水分获得的组织的血流量。其目标是确定动物如何适应单一激素的这些明显相互冲突的影响。这项研究将增加PI对血管紧张素II在动物脱水和再水化行为演变中所起的重要作用的了解