Comparative Physiology of Renal Transepithelial Phosphate Transport in Three Vertebrate Systems

9604070 Renfro无机磷酸盐在所有细胞中都有重要的功能，是骨骼和牙齿等身体结构成分的重要组成部分。生物体中磷酸盐的含量可以改变钙的平衡、体液的酸度和生长。膳食磷酸盐摄入量和肾脏排泄决定了正常代谢中无机磷酸盐的有效性。饮食中磷摄入不足可导致低磷血症，慢性低磷血症是一种潜在的有害状态，特别是在生长中的动物中。通过快速动员肌肉和骨骼中的磷酸盐来避免低磷血症。这可导致高钙血症和肾钙排泄增加。因此，肾脏的转运机制及其控制是研究的重要领域。磷酸盐的肾脏排泄受多种因素的调节或影响，包括血清磷酸盐浓度、酸碱平衡、钙代谢以及多种激素。在脊椎动物中，许多激素已被证明可以改变肾磷酸盐运输，但我们对这一过程的控制的理解是不完整的。最近，在包括哺乳动物（大鼠和人类）在内的其他脊椎动物中也发现了盐钙素和somotolactin这两种被认为是鱼类特有的激素。由于这些激素刺激磷素在比目鱼体内的转运，因此研究它们对其他脊椎动物体内磷素转运的影响是很重要的。伦弗洛博士将研究这些因素改变体内磷酸盐的过程。

9604070 Renfro Inorganic phosphate has important functions in all cells and is a vital part of structural components of the body such as bones and teeth. The amount of phosphate within an organism can alter calcium balance, acidity of body fluids, and growth. Dietary phosphate intake and renal excretion determine the availability of inorganic phosphate for normal metabolism. Inadequate dietary phosphorous intake can cause hypophosphatemia, which, if chronic is a potentially deleterious state, especially in a growing animal. Hypophosphatemia is avoided by rapid mobilization of phosphate from muscle and bone. This can result in hypercalcemia and increased renal calcium excretion. Thus, the kidney mechanisms of transport as well as their control are important areas of investigation. Renal excretion of phosphate is regulated, or otherwise influenced, by a variety of factors including serum phosphate concentration, acid-base balance, and calcium metabolism as well as a variety of hormones. In the vertebrates, a multitude of hormones has been shown to alter renal phosphate transport, but our understanding of the control of this process is incomplete. Recently, both stanniocalcin and somotolactin, hormones which were thought to be unique to fish, have been found in other vertebrate classes including mammals (rats and humans). Because these hormones stimulate phosphate transport in flounder, it is important to examine their effect on phosphate transport in other vertebrates. Dr. Renfro will examine the processes by which these factors alter body phosphate.