In:
American Journal of Physiology-Renal Physiology, American Physiological Society, Vol. 285, No. 4 ( 2003-10), p. F722-F730
Abstract:
In a previous paper, we found that low ionic strength (I) reversibly reduced the glomerular charge density, suggesting increased volume of the charge-selective barrier. Because glutaraldehyde makes most structures rigid, we considered the isolated, perfusion-fixed rat kidney to be an ideal model for further analysis. The fixed kidneys were perfused with albumin solutions containing FITC-Ficoll at two different Is (I = 151 and 34 mM). At normal I, the fractional clearance (θ) for albumin was 0.0049 (SE –0.0017, +0.0027, n = 6), whereas θ for neutral Ficoll 35.5Å of similar size was significantly higher 0.104 (SE 0.010, n = 5, P 〈 0.001). At low I, θ for albumin was 0.0030 (SE –0.0011, +0.0018, n = 6, not significant from θ albumin at normal I) and θ for Ficoll 35.5Å was identical to that at normal I, 0.104 (SE 0.015, n = 6, P 〈 0.01 compared with θ albumin at low I). According to a heterogeneous charged fiber model, low I reduced the fiber density from 0.056 to 0.0315, suggesting a 78% gel volume expansion. We conclude that 1) there is a significant glomerular charge barrier. 2) Solutions with low I increase the volume of the charge barrier even in kidneys fixed with glutaraldehyde. Our findings suggest that polysaccharide-rich structures, such as the endothelial cell coat, are key components in the glomerular barrier.
Type of Medium:
Online Resource
ISSN:
1931-857X
,
1522-1466
DOI:
10.1152/ajprenal.00227.2001
Language:
English
Publisher:
American Physiological Society
Publication Date:
2003
detail.hit.zdb_id:
1477287-5
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