The human kidney functions to rid the body of waste products, but also to regulate the salt and water composition of the blood and body fluids. Urea is a breakdown product of protein metabolism and generally perceived to be a waste product excreted by the kidney. This is indeed the case, but urea also plays an important role in normal kidney function. Urea is used in a complex manner by the kidney to augment concentration of the urine, such that only a small fraction of the initial urine formed in the kidney is actually excreted. Indeed, abnormal kidney function is reflected in changes in the amount of urea that is excreted - a condition called uremia. The mechanisms of cellular dysfunction in regards to urea are extremely difficult to study in human as well as laboratory mammals. Dr. Lacy will study shark and skate (elasmobranchs) kidney because of the following reasons: 1) Surprisingly, the skate kidney is remarkably similar in structure to that of humans, a finding Dr. Lacy made in 1985. 2) These animals have extremely high concentrations of urea in their blood and tissues, but the kidney does not excrete very much of it. 3) Skates are a more suitable alternative than laboratory rats for the PI's experimental animal. Dr. Lacy's research is directed to understanding how the skate kidney handles urea in its normal physiology. The PI's data will be applicable to human kidney function and disease.
