Hyperfiltration and inner stripe hypertrophy may explain findings by Gamble and coworkers

Anita T. Layton, Thomas L Pannabecker, William H Dantzler, Harold E. Layton

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Simulations conducted in a mathematical model were used to exemplify the hypothesis that elevated solute concentrations and tubular flows at the boundary of the renal outer and inner medullas of rats may contribute to increased urine osmolalities and urine flow rates. Such elevated quantities at that boundary may arise from hyperfiltration and from inner stripe hypertrophy, which are correlated with increased concentrating activity (Bankir L, Kriz W. Kidney Int. 47: 7-24, 1995). The simulations used the region-based model for the rat inner medulla that was presented in the companion study (Layton AT, Pannabecker TL, Dantzler WH, Layton HE. Am J Physiol Renal Physiol 298: F000-F000, 2010). The simulations were suggested by experiments which were conducted in rat by Gamble et al. (Gamble JL, McKhann CF, Butler AM, Tuthill E. Am J Physiol 109: 139-154, 1934) in which the ratio of NaCl to urea in the diet was systematically varied in eight successive 5-day intervals. The simulations predict that changes in boundary conditions at the boundary of the outer and inner medulla, accompanied by plausible modifications in transport properties of the collecting duct system, can significantly increase urine osmolality and flow rate. This hyperfiltrationhypertrophy hypothesis may explain the finding by Gamble et al. that the maximum urine osmolality attained from supplemental feeding of urea and NaCl in the eight intervals depends on NaCl being the initial predominant solute and on urea being the final predominant solute, because urea in sufficient quantity appears to stimulate concentrating activity. More generally, the hypothesis suggests that high osmolalities and urine flow rates may depend, in large part, on adaptive modifications of cortical hemodynamics and on outer medullary structure and not entirely on an extraordinary concentrating capability that is intrinsic to the inner medulla.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Renal Physiology
Volume298
Issue number4
DOIs
StatePublished - Apr 2010

Fingerprint

Hypertrophy
Osmolar Concentration
Urine
Urea
Kidney
Theoretical Models
Hemodynamics
Diet

Keywords

  • Countercurrent system
  • Mathematical model
  • NaCl transport
  • Renal inner medulla
  • Urea transport
  • Urine concentrating mechanism

ASJC Scopus subject areas

  • Physiology
  • Urology

Cite this

Hyperfiltration and inner stripe hypertrophy may explain findings by Gamble and coworkers. / Layton, Anita T.; Pannabecker, Thomas L; Dantzler, William H; Layton, Harold E.

In: American Journal of Physiology - Renal Physiology, Vol. 298, No. 4, 04.2010.

Research output: Contribution to journalArticle

@article{604006e0f71d4f5eb25fff71e29b2ba9,
title = "Hyperfiltration and inner stripe hypertrophy may explain findings by Gamble and coworkers",
abstract = "Simulations conducted in a mathematical model were used to exemplify the hypothesis that elevated solute concentrations and tubular flows at the boundary of the renal outer and inner medullas of rats may contribute to increased urine osmolalities and urine flow rates. Such elevated quantities at that boundary may arise from hyperfiltration and from inner stripe hypertrophy, which are correlated with increased concentrating activity (Bankir L, Kriz W. Kidney Int. 47: 7-24, 1995). The simulations used the region-based model for the rat inner medulla that was presented in the companion study (Layton AT, Pannabecker TL, Dantzler WH, Layton HE. Am J Physiol Renal Physiol 298: F000-F000, 2010). The simulations were suggested by experiments which were conducted in rat by Gamble et al. (Gamble JL, McKhann CF, Butler AM, Tuthill E. Am J Physiol 109: 139-154, 1934) in which the ratio of NaCl to urea in the diet was systematically varied in eight successive 5-day intervals. The simulations predict that changes in boundary conditions at the boundary of the outer and inner medulla, accompanied by plausible modifications in transport properties of the collecting duct system, can significantly increase urine osmolality and flow rate. This hyperfiltrationhypertrophy hypothesis may explain the finding by Gamble et al. that the maximum urine osmolality attained from supplemental feeding of urea and NaCl in the eight intervals depends on NaCl being the initial predominant solute and on urea being the final predominant solute, because urea in sufficient quantity appears to stimulate concentrating activity. More generally, the hypothesis suggests that high osmolalities and urine flow rates may depend, in large part, on adaptive modifications of cortical hemodynamics and on outer medullary structure and not entirely on an extraordinary concentrating capability that is intrinsic to the inner medulla.",
keywords = "Countercurrent system, Mathematical model, NaCl transport, Renal inner medulla, Urea transport, Urine concentrating mechanism",
author = "Layton, {Anita T.} and Pannabecker, {Thomas L} and Dantzler, {William H} and Layton, {Harold E.}",
year = "2010",
month = "4",
doi = "10.1152/ajprenal.00250.2009",
language = "English (US)",
volume = "298",
journal = "American Journal of Physiology",
issn = "0363-6143",
publisher = "American Physiological Society",
number = "4",

}

TY - JOUR

T1 - Hyperfiltration and inner stripe hypertrophy may explain findings by Gamble and coworkers

AU - Layton, Anita T.

AU - Pannabecker, Thomas L

AU - Dantzler, William H

AU - Layton, Harold E.

PY - 2010/4

Y1 - 2010/4

N2 - Simulations conducted in a mathematical model were used to exemplify the hypothesis that elevated solute concentrations and tubular flows at the boundary of the renal outer and inner medullas of rats may contribute to increased urine osmolalities and urine flow rates. Such elevated quantities at that boundary may arise from hyperfiltration and from inner stripe hypertrophy, which are correlated with increased concentrating activity (Bankir L, Kriz W. Kidney Int. 47: 7-24, 1995). The simulations used the region-based model for the rat inner medulla that was presented in the companion study (Layton AT, Pannabecker TL, Dantzler WH, Layton HE. Am J Physiol Renal Physiol 298: F000-F000, 2010). The simulations were suggested by experiments which were conducted in rat by Gamble et al. (Gamble JL, McKhann CF, Butler AM, Tuthill E. Am J Physiol 109: 139-154, 1934) in which the ratio of NaCl to urea in the diet was systematically varied in eight successive 5-day intervals. The simulations predict that changes in boundary conditions at the boundary of the outer and inner medulla, accompanied by plausible modifications in transport properties of the collecting duct system, can significantly increase urine osmolality and flow rate. This hyperfiltrationhypertrophy hypothesis may explain the finding by Gamble et al. that the maximum urine osmolality attained from supplemental feeding of urea and NaCl in the eight intervals depends on NaCl being the initial predominant solute and on urea being the final predominant solute, because urea in sufficient quantity appears to stimulate concentrating activity. More generally, the hypothesis suggests that high osmolalities and urine flow rates may depend, in large part, on adaptive modifications of cortical hemodynamics and on outer medullary structure and not entirely on an extraordinary concentrating capability that is intrinsic to the inner medulla.

AB - Simulations conducted in a mathematical model were used to exemplify the hypothesis that elevated solute concentrations and tubular flows at the boundary of the renal outer and inner medullas of rats may contribute to increased urine osmolalities and urine flow rates. Such elevated quantities at that boundary may arise from hyperfiltration and from inner stripe hypertrophy, which are correlated with increased concentrating activity (Bankir L, Kriz W. Kidney Int. 47: 7-24, 1995). The simulations used the region-based model for the rat inner medulla that was presented in the companion study (Layton AT, Pannabecker TL, Dantzler WH, Layton HE. Am J Physiol Renal Physiol 298: F000-F000, 2010). The simulations were suggested by experiments which were conducted in rat by Gamble et al. (Gamble JL, McKhann CF, Butler AM, Tuthill E. Am J Physiol 109: 139-154, 1934) in which the ratio of NaCl to urea in the diet was systematically varied in eight successive 5-day intervals. The simulations predict that changes in boundary conditions at the boundary of the outer and inner medulla, accompanied by plausible modifications in transport properties of the collecting duct system, can significantly increase urine osmolality and flow rate. This hyperfiltrationhypertrophy hypothesis may explain the finding by Gamble et al. that the maximum urine osmolality attained from supplemental feeding of urea and NaCl in the eight intervals depends on NaCl being the initial predominant solute and on urea being the final predominant solute, because urea in sufficient quantity appears to stimulate concentrating activity. More generally, the hypothesis suggests that high osmolalities and urine flow rates may depend, in large part, on adaptive modifications of cortical hemodynamics and on outer medullary structure and not entirely on an extraordinary concentrating capability that is intrinsic to the inner medulla.

KW - Countercurrent system

KW - Mathematical model

KW - NaCl transport

KW - Renal inner medulla

KW - Urea transport

KW - Urine concentrating mechanism

UR - http://www.scopus.com/inward/record.url?scp=77950847331&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77950847331&partnerID=8YFLogxK

U2 - 10.1152/ajprenal.00250.2009

DO - 10.1152/ajprenal.00250.2009

M3 - Article

C2 - 20042460

AN - SCOPUS:77950847331

VL - 298

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6143

IS - 4

ER -