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.
