RUI: Gill Na+/H+ Exchange in Marine Fish

这个项目的长期目标是了解海洋鱼类如何能够利用它们的鳃来完成哺乳动物肾脏所完成的许多相同的任务。鱼的鳃是一个多用途器官。类似于陆地动物的肺，鳃允许鱼呼吸氧气和排泄二氧化碳。此外，鱼鳃执行肝脏和肾脏的功能，因为它们可以消除有毒的代谢废物，如氨和酸。同样类似于肾脏，鳃通过调节动物血液中的盐分水平来帮助鱼。人们对鳃组织内部发生的实际细胞机制知之甚少。克莱本博士假设，一些咸水鱼可能会从周围的水中吸收盐（钠），以排出体内多余的酸。拥有这种能力的物种可能能够生活在更广泛的咸水环境中，从开阔的海洋到稀释的河口。本提案将研究两种不同种类的海鱼，剑鱼和蟾鱼的鳃机制。他的初步发现表明，当外部盐水平过低时，雕塑可能无法排出足够的酸。相比之下，蟾鱼可以在很大范围的盐水浓度中调节酸的水平。因此，通过比较这两种鱼类的酸排泄机制，将表明鳃是否在决定鱼类生存的环境盐度范围中起作用。此外，由于鳃内的这些细胞机制与目前在哺乳动物肾脏中研究的机制非常相似，因此对肾脏和其他器官生理学的新见解也可能得到阐明。＊＊＊

9419849 Claiborne The long range goal of this project is to understand how marine fish are able to use their gills to accomplish many of the same tasks that are performed by the kidneys in mammals. The fish gill is a multi-purpose organ. Analogous to the lungs in land-dwelling animals, the gills allow the fish to breath oxygen and excrete carbon dioxide. Further, the gills perform functions of the liver and kidneys as they eliminate toxic metabolic waste products like ammonia and acid. Also analogous to the kidneys, the gills assist the fish by regulating the levels of salts within the blood of the animal. Little is known about the actual cellular mechanisms which take place within the gill tissue. Dr. Claiborne has hypothesized that some saltwater fish may take in salt (sodium) from the surrounding water to excrete excess acid from within the body. The species which have this ability may then be able to live in a wider range of salt water environments, from the open ocean, to dilute estuaries. This proposal will study these gill mechanisms in two different species of marine fish, the sculpin, and the toadfish. His preliminary findings suggest that the sculpin may not be able to excrete sufficient acid when external salt levels are too low. In contrast, the toadfish can regulate acid levels in a wide range of saltwater concentrations. Thus, by comparing the acid excretion mechanisms in these two species, it will be shown whether the gills play a role in determining the environmental salinity range in which a fish species can live. Further, since these cellular mechanisms within the gills are very similar to those currently being studied in the mammalian kidney, new insights into the physiology of the kidney and other organs may also be elucidated. ***