Water Channel in Avian Kidney Collecting Duct

The University Of Tennessee, Memphis - The Health Science Center, Memphis TN

Investigators

Abstract

Water constitutes 60% of human body weight, and control of normal ion and water balance by the cardiovascular-renal system is extremely important for our health. An excess of body salt and water causes edema and hypertension, whereas fluid loss evokes cardiovascular malfunction, leading to hypertension and shock. Using a unique bird model, Dr. Nishimura will determine biochemical and molecular properties of the water channel in the kidney and examine how the kidney conserves or excretes water through this gate to maintain body fluid balance. She intends to 1) clone aquaporin, a water channel protein, using molecular techniques; 2) study its cellular localization and function using a Xenopus oocyte expression system; and 3) examine its control by hormones. Only avian and mammalian kidneys can concentrate urine, and bird kidneys possess both primitive and more advanced anatomical/functional features; thus, the bird model is useful for answering fundamental questions about the mechanisms of water balance. Such studies will elucidate the phylogenetic modulation of water channels during adaptation of animals from aquatic to terrestrial environments and help us understand the mechanisms working in humans in health and disease.