| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; and 2 Department of Medicine, University of Minnesota, Minneapolis, Minnesota 55455
The extent to which the glomerular basement membrane (GBM) contributes to the charge selectivity of the glomerular capillary wall has been controversial. To reexamine this issue, the size and charge selectivity of filters made from isolated rat GBM were assessed, using polydisperse Ficoll and Ficoll sulfate as test macromolecules. Ficoll sulfate, a novel tracer with spherical shape synthesized for this purpose, exhibited little or no binding to serum albumin, thereby avoiding a major difficulty that has been reported with dextran sulfate. The sieving coefficients of Ficoll sulfate were not different from those of Ficoll at physiological ionic strength, although the values for Ficoll sulfate were depressed at low ionic strength. These results confirm that the GBM possesses fixed negative charges but suggest that its charge density is insufficient to confer significant charge selectivity under physiological conditions, where electrostatic interactions are relatively well screened. The sieving coefficients of Ficoll sulfate and Ficoll were elevated significantly and by similar amounts when bovine serum albumin (BSA) was present in the retentate at 4 g/dl. This could be explained as the combined effect of two nonspecific physical factors, namely, the reduction in filtration velocity due to the osmotic pressure of BSA and the effect on macromolecular partitioning of repulsive solute-solute interactions. The view that BSA does not affect the intrinsic properties of the GBM is supported also by the absence of an effect on the hydraulic permeability of isolated GBM. The sieving coefficient of BSA was roughly half that of Ficoll or Ficoll sulfate of similar Stokes-Einstein radius. Given the finding of negligible charge selectivity, this difference may be attributed to the nonspherical shape of albumin. The results suggest that, to the extent that isolated GBM is similar to GBM in vivo, the charge selectivity of the glomerular capillary wall must be due to the endothelial and/or epithelial cell layers.
sieving coefficient; hydraulic permeability; albumin permeability
This article has been cited by other articles:
|
|
 |
|
  B. Haraldsson, J. Nystrom, and W. M. Deen Properties of the Glomerular Barrier and Mechanisms of Proteinuria Physiol Rev, April 1, 2008; 88(2): 451 - 487. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Asgeirsson, D. Venturoli, B. Rippe, and C. Rippe Increased glomerular permeability to negatively charged Ficoll relative to neutral Ficoll in rats Am J Physiol Renal Physiol, November 1, 2006; 291(5): F1083 - F1089. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Bjornson Granqvist, K. Ebefors, M. A. Saleem, P. W. Mathieson, B. Haraldsson, and J. S. Nystrom Podocyte proteoglycan synthesis is involved in the development of nephrotic syndrome Am J Physiol Renal Physiol, October 1, 2006; 291(4): F722 - F730. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Jeansson and B. Haraldsson Morphological and functional evidence for an important role of the endothelial cell glycocalyx in the glomerular barrier Am J Physiol Renal Physiol, January 1, 2006; 290(1): F111 - F116. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Venturoli and B. Rippe Ficoll and dextran vs. globular proteins as probes for testing glomerular permselectivity: effects of molecular size, shape, charge, and deformability Am J Physiol Renal Physiol, April 1, 2005; 288(4): F605 - F613. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Bjornson, J. Moses, A. Ingemansson, B. Haraldsson, and J. Sorensson Primary human glomerular endothelial cells produce proteoglycans, and puromycin affects their posttranslational modification Am J Physiol Renal Physiol, April 1, 2005; 288(4): F748 - F756. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Haraldsson and J. Sorensson Why Do We Not All Have Proteinuria? An Update of Our Current Understanding of the Glomerular Barrier Physiology, February 1, 2004; 19(1): 7 - 10. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. M. Guimaraes, J. Nikolovski, L. M. Pratt, K. Greive, and W. D. Comper Anomalous fractional clearance of negatively charged Ficoll relative to uncharged Ficoll Am J Physiol Renal Physiol, December 1, 2003; 285(6): F1118 - F1124. [Abstract] [Full Text]
|
|
|
|
 |
|
 M. Jeansson and B. Haraldsson Glomerular Size and Charge Selectivity in the Mouse after Exposure to Glucosaminoglycan-Degrading Enzymes J. Am. Soc. Nephrol., July 1, 2003; 14(7): 1756 - 1765. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
U. Lund, A. Rippe, D. Venturoli, O. Tenstad, A. Grubb, and B. Rippe Glomerular filtration rate dependence of sieving of albumin and some neutral proteins in rat kidneys Am J Physiol Renal Physiol, June 1, 2003; 284(6): F1226 - F1234. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Pavenstadt, W. Kriz, and M. Kretzler Cell Biology of the Glomerular Podocyte Physiol Rev, January 1, 2003; 83(1): 253 - 307. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Lazzara and W. M. Deen Effects of plasma proteins on sieving of tracer macromolecules in glomerular basement membrane Am J Physiol Renal Physiol, November 1, 2001; 281(5): F860 - F868. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. M. Deen, M. J. Lazzara, and B. D. Myers Structural determinants of glomerular permeability Am J Physiol Renal Physiol, October 1, 2001; 281(4): F579 - F596. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. A. Greive, D. J. Nikolic-Paterson, M. A. M. Guimaraes, J. Nikolovski, L. M. Pratt, W. Mu, R. C. Atkins, and W. D. Comper Glomerular Permselectivity Factors Are Not Responsible for the Increase in Fractional Clearance of Albumin in Rat Glomerulonephritis Am. J. Pathol., September 1, 2001; 159(3): 1159 - 1170. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Sorensson, M. Ohlson, and B. Haraldsson A quantitative analysis of the glomerular charge barrier in the rat Am J Physiol Renal Physiol, April 1, 2001; 280(4): F646 - F656. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Ohlson, J. Sorensson, and B. Haraldsson A gel-membrane model of glomerular charge and size selectivity in series Am J Physiol Renal Physiol, March 1, 2001; 280(3): F396 - F405. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. MACCONI, M. GHILARDI, M. E. BONASSI, E. I. MOHAMED, M. ABBATE, F. COLOMBI, G. REMUZZI, and A. REMUZZI Effect of Angiotensin-Converting Enzyme Inhibition on Glomerular Basement Membrane Permeability and Distribution of Zonula Occludens-1 in MWF Rats J. Am. Soc. Nephrol., March 1, 2000; 11(3): 477 - 489. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Edwards, B. S. Daniels, and W. M. Deen Ultrastructural model for size selectivity in glomerular filtration Am J Physiol Renal Physiol, June 1, 1999; 276(6): F892 - F902. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
