Regulation of solute and water balance in primitive fishes

内分泌对溶质和水分平衡的调控是所有生物体的生命维持过程。它需要许多不同的生理系统通过多种激素的相互作用来协调行动。血管紧张素II、C型利钠肽、缓激肽和精氨酸缩血管素等激素均参与哺乳动物的水、溶质调节。研究表明，这些激素也存在，并具有生理功能，在生殖系统古老的板鳃鱼。拟议的研究计划将探讨这些激素在调节板鳃鱼的肾脏、心血管和胃肠生理方面所起的作用。此外，尿素和氨的关键转运蛋白的分子特征将提供新的信息氮平衡在板鳃类。此外，尿素分解细菌可能在这些原始鱼类的氮代谢中发挥的作用也将被研究。拟议的研究是重要的，因为它的目的是提供一个进化的框架，在脊椎动物中的溶质运输机制和生理的了解激素系统如何调节类似的生理功能，在板鳃鱼类。进一步的研究，建议检查钙运输和内分泌调节这一关键离子在第二原始鱼类，湖鲟鱼。这些淡水软骨鱼在钙调节方面呈现出独特的模式。分子表征的运输机制，除了激素调节这种离子将有助于我们了解钙代谢在这些鱼，因此，拟议的研究将有助于减轻潜在的影响，在记录下降的环境钙可能对这个受威胁的物种。因此，从这项拟议的研究计划中获得的信息不仅可以用于工业领域，因为这项基础研究支持制药业治疗方法开发中更先进和创新的研究，而且还可以用于保护濒危物种（如湖鲟）的保护生理学。

Endocrine control of solute and water balance is a life sustaining process in all organisms. It requires the coordinated action of a number of different physiological systems through the interaction of a multitude of hormones. Hormones such as angiotensin II, C-type natriuretic peptide, bradykinin and arginine vasotocin are all involved in solute and water regulation in mammals. Research has shown that these hormones also exist, and have physiological function, in the phylogenetically ancient elasmobranch fish. The proposed research programme will examine the role these hormones play in the regulation of renal, cardiovascular and gastro-intestinal physiology of elasmobranch fish. In addition, molecular characterisation of key transport proteins for urea and ammonia will provide new information on nitrogen balance in elasmobranchs. Furthermore, the role ureolytic bacteria may play in nitrogen metabolism in these primitive fish will be examined. The proposed research is significant as it aims to provide an evolutionary framework for solute transport mechanisms in vertebrates and a physiological understanding of how hormone systems regulate similar physiological functions in elasmobranch fish. Additional research is proposed to examine calcium transport and the endocrine regulation of this key ion in a second primitive fish, the lake sturgeon. These freshwater cartilaginous fish present a unique model in terms of calcium regulation. Molecular characterisation of transport mechanisms in addition to hormonal regulation of this ion will aid in our understanding of calcium metabolism in these fish and therefore the proposed research will aid in the mitigation of potential impacts in the documented declines of environmental calcium may have on this threatened species. Therefore, information gained from this proposed research programme can be used not only in the context of industry as this fundamental research underpins more advanced and innovative research in the development of therapeutics in the pharmaceutical industry but also from the context of conservation physiology for the protection of threatened species such as the lake sturgeon.