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Glomerular filtration rate dependence of sieving of albumin and some neutral proteins in rat kidneys

Lund, Ulla LU ; Rippe, Anna LU ; Venturoli, Daniele LU ; Tenstad, O; Grubb, Anders LU and Rippe, Bengt LU (2003) In American Journal of Physiology: Renal, Fluid and Electrolyte Physiology 284(6). p.1226-1234
Abstract
The size and charge-selective properties of the glomerular barrier are partly controversial. Glomerular sieving coefficients (theta) for proteins have rarely been determined noninvasively before in vivo. Therefore, theta was assessed vs. glomerular filtration rate (GFR; Cr-51-EDTA clearance) in intact rats for radiolabeled myoglobin, kappa-dimer, neutral horseradish peroxidase (nHRP), neutral human serum albumin (nHSA), and native albumin (HSA). To obtain theta, glomerular tracer clearance, assessed from the 7- to 8-min kidney uptake of protein, was divided by the GFR. The data were fitted with a two-pore model of glomerular permeability, where the small-pore radius was 37.35 +/- 1.11(SE) Angstrom, and the "unrestricted pore area over... (More)
The size and charge-selective properties of the glomerular barrier are partly controversial. Glomerular sieving coefficients (theta) for proteins have rarely been determined noninvasively before in vivo. Therefore, theta was assessed vs. glomerular filtration rate (GFR; Cr-51-EDTA clearance) in intact rats for radiolabeled myoglobin, kappa-dimer, neutral horseradish peroxidase (nHRP), neutral human serum albumin (nHSA), and native albumin (HSA). To obtain theta, glomerular tracer clearance, assessed from the 7- to 8-min kidney uptake of protein, was divided by the GFR. The data were fitted with a two-pore model of glomerular permeability, where the small-pore radius was 37.35 +/- 1.11(SE) Angstrom, and the "unrestricted pore area over diffusion path length" (A(0)/DeltaX) 1.84 +/- 0.43 . 10(6) cm. Although seemingly horizontal for nHRP and nHSA, the log theta vs. GFR curves showed slightly negative slopes for the proteins investigated in the GFR interval of 2-4.5 ml/min. Strong negative ( linear) correlations between ( log) theta and GFR were obtained for myoglobin (P = 0.002) and HSA (P = 0.006), whereas they were relatively weak for nHRP and nHSA and nonsignificant for kappa-dimer. theta for nHSA was markedly higher than that for HSA. In conclusion, there were no indications of increases in theta vs. GFR, as indicative of concentration polarization, for the proteins investigated at high GFRs. Furthermore, the glomerular small-pore radius assessed from endogenous (neutral) protein sieving data was found to be smaller than previously determined using dextran or Ficoll as test molecules. (Less)
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author
organization
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type
Contribution to journal
publication status
published
subject
keywords
glomerular permeability, transport, reflection coefficient, macromolecules
in
American Journal of Physiology: Renal, Fluid and Electrolyte Physiology
volume
284
issue
6
pages
1226 - 1234
publisher
American Physiological Society
external identifiers
  • wos:000182700200012
  • pmid:12620929
  • scopus:0037609543
ISSN
0363-6127
DOI
language
English
LU publication?
yes
id
eba789a6-dad5-4823-b8e9-065c92ed8274 (old id 312332)
date added to LUP
2007-09-17 18:17:07
date last changed
2018-06-10 03:49:13
@article{eba789a6-dad5-4823-b8e9-065c92ed8274,
  abstract     = {The size and charge-selective properties of the glomerular barrier are partly controversial. Glomerular sieving coefficients (theta) for proteins have rarely been determined noninvasively before in vivo. Therefore, theta was assessed vs. glomerular filtration rate (GFR; Cr-51-EDTA clearance) in intact rats for radiolabeled myoglobin, kappa-dimer, neutral horseradish peroxidase (nHRP), neutral human serum albumin (nHSA), and native albumin (HSA). To obtain theta, glomerular tracer clearance, assessed from the 7- to 8-min kidney uptake of protein, was divided by the GFR. The data were fitted with a two-pore model of glomerular permeability, where the small-pore radius was 37.35 +/- 1.11(SE) Angstrom, and the "unrestricted pore area over diffusion path length" (A(0)/DeltaX) 1.84 +/- 0.43 . 10(6) cm. Although seemingly horizontal for nHRP and nHSA, the log theta vs. GFR curves showed slightly negative slopes for the proteins investigated in the GFR interval of 2-4.5 ml/min. Strong negative ( linear) correlations between ( log) theta and GFR were obtained for myoglobin (P = 0.002) and HSA (P = 0.006), whereas they were relatively weak for nHRP and nHSA and nonsignificant for kappa-dimer. theta for nHSA was markedly higher than that for HSA. In conclusion, there were no indications of increases in theta vs. GFR, as indicative of concentration polarization, for the proteins investigated at high GFRs. Furthermore, the glomerular small-pore radius assessed from endogenous (neutral) protein sieving data was found to be smaller than previously determined using dextran or Ficoll as test molecules.},
  author       = {Lund, Ulla and Rippe, Anna and Venturoli, Daniele and Tenstad, O and Grubb, Anders and Rippe, Bengt},
  issn         = {0363-6127},
  keyword      = {glomerular permeability,transport,reflection coefficient,macromolecules},
  language     = {eng},
  number       = {6},
  pages        = {1226--1234},
  publisher    = {American Physiological Society},
  series       = {American Journal of Physiology: Renal, Fluid and Electrolyte Physiology},
  title        = {Glomerular filtration rate dependence of sieving of albumin and some neutral proteins in rat kidneys},
  url          = {http://dx.doi.org/},
  volume       = {284},
  year         = {2003},
}