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Review
. 2015 Jan-Feb;35(1):9-13.
doi: 10.3747/pdi.2014.00110.

Counterpoint: Defending pore theory

Bengt Rippe  1 , Carl M Öberg  2
Affiliations
Review

Counterpoint: Defending pore theory

Bengt Rippe et al. Perit Dial Int. 2015 Jan-Feb.
No abstract available

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Figures

FIGURE 1 —
FIGURE 1 —
“New” (A) and “old” (B) “Brenner curves” (1). Panel A shows recent data on glomerular sieving coefficients measured for anionic and neutral Ficoll and simulated for cationic Ficoll (14). The negatively charged Ficoll molecules (hatched line) were calculated to have a surface charge of similar magnitude to albumin (-0.02 C/m2) (16). The surface charge of the positively charged Ficoll was set at 0.02 C/m2. B represents the “classical” Brenner curves measured for negatively charged, sulfated dextran vs neutral and cationic (DEAE) dextran. The sulfated dextran measurements (hatched line) especially have been found to be in error and to markedly exaggerate the impact of charge on the properties of the glomerular filtration barrier.
FIGURE 2 —
FIGURE 2 —
Glomerular sieving curves for negatively charged molecules modeled as hard spheres with a surface charge of -0.02 C/m2 for 3 different field strengths: 0 V/m, -1,600 V/m (25) and 4,800 V/m. A 2-pore model was employed, where the small pore radius (rs) was set at 36.6 Å, the large pore radius (rL) at 98.6 Å, and the fractional ultrafiltration coefficient accounted for by large pores (αL) at 6 × 10-5 (33). Neither the streaming potential reported by Hausmann et al. (25), nor the hypothetical field strength generated by a (1.5 mV) Donnan potential (4,800 V/m) significantly affected the transport of charged solutes across the GFB. The effects are particularly low for a solute the size of albumin. Note that a (small) reversed streaming potential would be totally counteracted by the effect of the Donnan potential.
See this image and copyright information in PMC

References

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