The primary goal of this project is now limited to increasing our understanding of amino acid transport in individual nephron segments of the renal medulla by determining the mechanisms involved in amino acid transport and apparent recycling among loops of Henle and vasa recta. The title of the project has been changed to reflect this more specific goal. The planned studies will take advantage of technical improvements permitting study both in vivo and in vitro of equivalent segments of loops of Henle from Munich-Wistar rats. Determination of mechanisms involved in amino acid transport and apparent recycling in the mammalian medulla will involve: 1) in vivo continuous microinfusions of papillary loops of Henle and vasa recta; 2) in vitro microperfusions of descending and ascending thin limbs and ascending thick limbs of loops of Henle of juxtamedullary nephrons; and 3) in vitro microperfusions of descending and ascending limbs of loops of Henle of superficial cortical nephrons. These studies will involve measurements of fluxes of radiolabeled amino acids and chemical analyses of amino acids. They will examine factors regulating the fluxes. The results will contribute to the understanding of the role of amino acids in medullary function.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK016294-24
Application #
2882753
Study Section
General Medicine B Study Section (GMB)
Program Officer
Scherbenske, M James
Project Start
1978-12-01
Project End
2000-02-29
Budget Start
1999-03-01
Budget End
2000-02-29
Support Year
24
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Arizona
Department
Physiology
Type
Schools of Medicine
DUNS #
City
Tucson
State
AZ
Country
United States
Zip Code
85721
Dantzler, W H; Pannabecker, T L; Layton, A T et al. (2011) Urine concentrating mechanism in the inner medulla of the mammalian kidney: role of three-dimensional architecture. Acta Physiol (Oxf) 202:361-78
Layton, Anita T; Pannabecker, Thomas L; Dantzler, William H et al. (2010) Functional implications of the three-dimensional architecture of the rat renal inner medulla. Am J Physiol Renal Physiol 298:F973-87
Layton, Anita T; Pannabecker, Thomas L; Dantzler, William H et al. (2010) Hyperfiltration and inner stripe hypertrophy may explain findings by Gamble and coworkers. Am J Physiol Renal Physiol 298:F962-72
Yuan, Justin; Pannabecker, Thomas L (2010) Architecture of inner medullary descending and ascending vasa recta: pathways for countercurrent exchange. Am J Physiol Renal Physiol 299:F265-72
Kim, Julie; Pannabecker, Thomas L (2010) Two-compartment model of inner medullary vasculature supports dual modes of vasopressin-regulated inner medullary blood flow. Am J Physiol Renal Physiol 299:F273-9
Layton, Anita T; Layton, Harold E; Dantzler, William H et al. (2009) The mammalian urine concentrating mechanism: hypotheses and uncertainties. Physiology (Bethesda) 24:250-6
Pannabecker, Thomas L (2008) Loop of Henle interaction with interstitial nodal spaces in the renal inner medulla. Am J Physiol Renal Physiol 295:F1744-51
Pannabecker, Thomas L; Henderson, Cory S; Dantzler, William H (2008) Quantitative analysis of functional reconstructions reveals lateral and axial zonation in the renal inner medulla. Am J Physiol Renal Physiol 294:F1306-14
Pannabecker, Thomas L; Dantzler, William H; Layton, Harold E et al. (2008) Role of three-dimensional architecture in the urine concentrating mechanism of the rat renal inner medulla. Am J Physiol Renal Physiol 295:F1271-85
Pannabecker, Thomas L; Dantzler, William H (2007) Three-dimensional architecture of collecting ducts, loops of Henle, and blood vessels in the renal papilla. Am J Physiol Renal Physiol 293:F696-704

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