|
|
||||||||
AJP - Renal Physiology, Vol 253, Issue 5 1020-F1030, Copyright © 1987 by American Physiological Society
ARTICLES |
A. S. Wexler, R. E. Kalaba and D. J. Marsh
Department of Physiology and Biophysics, School of Medicine, University of Southern California, Los Angeles 90033.
Simulations were performed to test the ability of the countercurrent hypothesis to predict measured concentrations of NaCl and urea in the interstitium of the renal medulla. The simulations included one-dimensional representations of loops of Henle, distal tubules, collecting ducts, and vasa recta, and recent estimates of descending limb, thick ascending limb, and collecting duct transport parameters. The nonlinear two-point boundary value problem was solved numerically via quasi-linearization. The simulations failed to predict measured concentrations or concentration gradients of NaCl in the inner medulla. Including countertransport of urea and NaCl in thin ascending limbs added minimally to the performance of the system. The single most effective change in the model was the inclusion of a coefficient to permit preferential solute exchange among vasa recta. This result suggests that the three-dimensional ordering of blood vessels and tubules is an essential construct in the concentrating mechanism.
This article has been cited by other articles:
![]() |
T. L. Pannabecker, W. H. Dantzler, H. E. Layton, and A. T. Layton Role of three-dimensional architecture in the urine concentrating mechanism of the rat renal inner medulla Am J Physiol Renal Physiol, November 1, 2008; 295(5): F1271 - F1285. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Knepper, G. M. Saidel, V. C. Hascall, and T. Dwyer Concentration of solutes in the renal inner medulla: interstitial hyaluronan as a mechano-osmotic transducer Am J Physiol Renal Physiol, March 1, 2003; 284(3): F433 - F446. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Hervy and S. R. Thomas Inner medullary lactate production and urine-concentrating mechanism: a flat medullary model Am J Physiol Renal Physiol, January 1, 2003; 284(1): F65 - F81. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. R. Thomas Cycles and separations in a model of the renal medulla Am J Physiol Renal Physiol, November 1, 1998; 275(5): F671 - F690. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |