Update on the glomerular filtration barrier

Research output: Contribution to journalReview articlepeer-review

91 Scopus citations

Abstract

PURPOSE OF REVIEW: The nephrology community lacks a unified view of protein sieving through the glomerular capillary wall. The glomerular capillary wall consists of three distinct but closely interacting layers: the fenestrated endothelium, with its glycocalyx; the podocytes, with their interdigitated foot processes and slit diaphragms; and the intervening glomerular basement membrane. Proteinuria is associated with abnormalities in any one layer, suggesting that each contributes to the glomerular filtration barrier (GFB). Proteinuria can also be induced in the context of a normal glomerular capillary wall. Here, we review some classic studies as well as some newer concepts and present competing hypotheses about the GFB. RECENT FINDINGS: Two almost forgotten concepts have recently emerged. One group has challenged the exquisite selectivity of the GFB to albumin and suggested that proteinuria is the result of abnormal tubular uptake. There has also been a reemphasis on diffusion through the glomerular basement membrane as the driving force behind macromolecular filtration. New evidence suggests that the endothelial glycocalyx is an important charge-selective barrier. SUMMARY: We suggest viewing the GFB as a dynamic rather than as a rigid barrier, requiring three healthy layers and a hemodynamic steady state. Multiple challenges to studying the endothelium, the tubular handling of albumin, and the role of hemodynamic forces will require new tools, new hypotheses, and open minds.

Original languageEnglish
Pages (from-to)226-232
Number of pages7
JournalCurrent Opinion in Nephrology and Hypertension
Volume18
Issue number3
DOIs
StatePublished - May 2009

Keywords

  • Gel permeation
  • Glomerular filtration barrier
  • Permselectivity
  • Proteinuria
  • podocytes

Fingerprint Dive into the research topics of 'Update on the glomerular filtration barrier'. Together they form a unique fingerprint.

Cite this