Differentiation of glomerular filter and tubular reabsorption apparatus during foetal development of the rat kidney

Development ◽  
1980 ◽  
Vol 58 (1) ◽  
pp. 157-175
Author(s):  
Jean Schaeverbeke ◽  
Madeleine Cheignon
Keyword(s):  
Molecular Weight ◽  
Basement Membrane ◽  
Proximal Tubule ◽  
High Molecular Weight ◽  
Glomerular Basement Membrane ◽  
Rat Kidney ◽  
Tubular Reabsorption ◽  
Foetal Development ◽  
Endocytic Vesicles ◽  
Glomerular Barrier

Differentiation of the glomerulus and the proximal tubule was studied in the rat foetus, especially with regard to the development of the protein filtration-reabsorption apparatus. Filtration starts several days before full differentiation of the glomerulus, when the glomerular basement membrane consists of a thin lamina alongside the podocyte membrane. Endocytosis is functional from this time, but fusion between endocytic vesicles and lysosome-like bodies occurs 2 days later. Foetal urine electrophoresis shows the presence of many proteins, including high molecular weight ones, this proteinuria seeming chiefly due to the immaturity of the glomerular barrier.

Permeability of the Macula densa Basement Membrane Area to High Molecular Weight Molecules

1992 ◽  
Vol 15 (2) ◽  
pp. 89-98 ◽  
Author(s):  
Darwin Bell ◽  
Patricia L. St. John ◽  
Matthew Speyer ◽  
Dale R. Abrahamson
Keyword(s):  
Molecular Weight ◽  
Basement Membrane ◽  
High Molecular Weight ◽  
Macula Densa ◽  
Membrane Area

scholarly journals Glomerular permeability is not affected by heparan sulfate glycosaminoglycan deficiency in zebrafish embryos

2019 ◽  
Vol 317 (5) ◽  
pp. F1211-F1216 ◽  
Author(s):  
Ramzi Khalil ◽  
Reshma A. Lalai ◽  
Malgorzata I. Wiweger ◽  
Cristina M. Avramut ◽  
Abraham J. Koster ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Heparan Sulfate ◽  
Glomerular Filtration ◽  
Glomerular Basement Membrane ◽  
Experimental Models ◽  
Tubular Reabsorption ◽  
Glomerular Filtration Barrier ◽  
Glomerular Permeability ◽  
Tracer Injection ◽  
Filtration Barrier

Proteinuria develops when specific components in the glomerular filtration barrier have impaired function. Although the precise components involved in maintaining this barrier have not been fully identified, heparan sulfate proteoglycans are believed to play an essential role in maintaining glomerular filtration. Although in situ studies have shown that a loss of heparan sulfate glycosaminoglycans increases the permeability of the glomerular filtration barrier, recent studies using experimental models have shown that podocyte-specific deletion of heparan sulfate glycosaminoglycan assembly does not lead to proteinuria. However, tubular reabsorption of leaked proteins might have masked an increase in glomerular permeability in these models. Furthermore, not only podocytes but also glomerular endothelial cells are involved in heparan sulfate synthesis in the glomerular filtration barrier. Therefore, we investigated the effect of a global heparan sulfate glycosaminoglycan deficiency on glomerular permeability. We used a zebrafish embryo model carrying a homozygous germline mutation in the ext2 gene. Glomerular permeability was assessed with a quantitative dextran tracer injection method. In this model, we accounted for tubular reabsorption. Loss of anionic sites in the glomerular basement membrane was measured using polyethyleneimine staining. Although mutant animals had significantly fewer negatively charged areas in the glomerular basement membrane, glomerular permeability was unaffected. Moreover, heparan sulfate glycosaminoglycan-deficient embryos had morphologically intact podocyte foot processes. Glomerular filtration remains fully functional despite a global reduction of heparan sulfate.

scholarly journals Anionic charge concentration of rat kidney glomeruli and glomerular basement membrane

1993 ◽  
Vol 289 (3) ◽  
pp. 647-652 ◽  
Author(s):  
W D Comper ◽  
A S N Lee ◽  
M Tay ◽  
Y Adal
Keyword(s):  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Electrostatic Interactions ◽  
Enzyme Inhibitors ◽  
Rat Kidney ◽  
Basement Membranes ◽  
Sulphate Content ◽  
Anionic Charge ◽  
Charge Concentration ◽  
A Charge

Estimates of levels of glomerular and glomerular-basement-membrane anion charge should serve as useful quantitative markers for the integrity of the tissues in health and disease. We have developed a simple, rapid, technique to measure this charge through the use of ion exchange with radioisotopes 22Na+ and 36Cl- at low ionic strengths in phosphate buffer. When this technique is used, normal glomeruli isolated from rat have a measured net anion charge concentration of 17.4 +/- 3.7 p-equiv. per glomerulus (n = 20). Perfused rat kidneys that lose approximately half of their glomerular heparan [35S]sulphate content (owing to oxygen-radical damage) exhibited a lower anion charge, of 7.5 +/- 1.6 p-equiv. per glomerulus (n = 5). Glomerular basement membranes prepared from rat glomeruli by a sonication-centrifugation procedure in the presence of enzyme inhibitors had a charge concentration of 6.3 +/- 0.7 mu-equiv./g wet wt. of tissue (n = 4), whereas membranes prepared by sonication, centrifugation, DNAse and detergent treatment had a charge concentration of 7.1 +/- 1.6 mu-equiv./g wet wt. (n = 4). Isotope-dilution experiments with 3H2O on these detergent-prepared glomerular basement membranes demonstrated that they had a water content of approx. 93%, which would then give a net anion charge concentration of 7.6 +/- 1.7 m-equiv./l (n = 4). These values are in good agreement with those obtained by others using titration techniques [Bray and Robinson (1984) Kidney Int. 25, 527-533]. The relatively low magnitude of glomerular anion charge in normal kidneys is consistent with other recent findings that glomerular anion charge is too low to affect the glomerular transport of charged molecules in a direct, passive, biophysical manner through electrostatic interactions.

Synthesis of the glomerular basement membrane in the rat kidney

1976 ◽  
Vol 20 (1) ◽  
pp. 125-137
Author(s):  
W. Romen ◽  
B. Schultze ◽  
K. Hempel
Keyword(s):  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Rat Kidney

scholarly journals Arterial basement-membrane-like material isolated and characterized from rabbit aortic myomedial cells in culture

1983 ◽  
Vol 211 (2) ◽  
pp. 397-404 ◽  
Author(s):  
L Heickendorff ◽  
T Ledet
Keyword(s):  
Molecular Weight ◽  
Basement Membrane ◽  
High Molecular Weight ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Periodic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Type I

Arterial basement-membrane-like material was isolated from rabbit aortic myomedial cell cultures by sonication and differential centrifugation. Isolated basement-membrane-like material was shown to be free of both cellular and matrix contaminants, on the basis of determinations of DNA, RNA, cholesterol, phosphorus and (Na+ + K+)-activated ATPase, combined with electron microscopy. Amino acid analyses showed that arterial basement-membrane-like material was composed of predominantly non-collagenous amino acids. Evaluated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, reduced basement-membrane-like material comprised six major and about 30 minor components in the Mr range 10 000-600 000. One of the major peptides (Mr 225 000) was disulphide-linked. Periodic acid-Schiff staining of gels indicated that most high-molecular-weight components were glycoproteins. Two-dimensional gel electrophoresis resolved reduced basement-membrane-like material into more than 100 components, with pI from 5 to 7. The disulphide-linked Mr-225 000 peptide appeared heterogeneous, with pI of 5.6-6.0, and was considered to represent fibronectin. All major peptides were of non-collagenous nature, on the basis of their susceptibility to pepsin and resistance to collagenase. Purified myomedial basement-membrane-like material contained collagenous peptides, as indicated by the presence of hydroxyproline and hydroxylysine. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of pepsin-treated and reduced basement-membrane-like material revealed five high-molecular-weight collagenous components appearing in the Mr range 105 000-375 000 relative to type I collagen standards.

Effect of bradykinin and kininogens in isolated rat kidney vasoconstricted by angiotensin II

1990 ◽  
Vol 258 (5) ◽  
pp. F1273-F1281 ◽  
Author(s):  
J. Gardes ◽  
T. Baussant ◽  
P. Corvol ◽  
J. Menard ◽  
F. Alhenc-Gelas
Keyword(s):  
Molecular Weight ◽  
Angiotensin Ii ◽  
High Molecular Weight ◽  
Rat Kidney ◽  
Renin Secretion ◽  
Ang Ii ◽  
Urinary Kallikrein ◽  
High Molecular Weight Kininogen ◽  
Perfusate Flow ◽  
Isolated Rat

The hemodynamic and endocrine effects of bradykinin and kininogens were investigated using a closed-circuit isolated rat kidney perfused with angiotensin II (ANG II). ANG II induced vasoconstriction, stimulation of urinary kallikrein release, and inhibition of renin secretion. Bradykinin markedly increased renal perfusate flow (RPF) and produced a slight but significant diuresis and natriuresis. The inhibitory effect of ANG II on renin secretion was delayed. Urinary kallikrein secretion was unchanged. The effect of bradykinin was suppressed by the competitive kinin antagonist [DArg,Hyp3,Thi5,8,DPhe7]bradykinin. Kallikrein-sensitive rat high-molecular-weight kininogen produced a progressive rise in renal perfusate flow. Exocrine function and renin and kallikrein secretions were unchanged. Immunoreactive kinins, identified as bradykinin by high-pressure liquid chromatography, were liberated into the perfusate. Perfusate immunoreactive high-molecular-weight kininogen decreased in parallel as a result of consumption. The kalikrein-resistant T-kininogen was not hydrolyzed to release a kinin, had no effect on renal function, and its concentration in the perfusate remained constant. These results suggest that kinin can be produced in the renal circulation from kallikrein-sensitive circulating kininogens and can antagonize the vasoconstrictor effect of ANG II and alter renal hemodynamics. They provide evidence that the kallikrein-kinin system can participate with the renin-angiotensin system in the control of renal blood flow.

Cell fractionation and electron microscope studies of kidney folate-binding protein

1991 ◽  
Vol 260 (2) ◽  
pp. C338-C346 ◽  
Author(s):  
J. T. Hjelle ◽  
E. I. Christensen ◽  
F. A. Carone ◽  
J. Selhub
Keyword(s):  
Electron Microscope ◽  
Proximal Tubule ◽  
Brush Border ◽  
Binding Protein ◽  
Rat Kidney ◽  
Proximal Tubules ◽  
Cell Fractionation ◽  
Folate Binding Protein ◽  
Em Autoradiography ◽  
Endocytic Vesicles

The subcellular distribution of folate-binding protein (FBP) and [3H]folate in the proximal tubule was examined using cell fractionation and different electron microscope (EM) techniques. Cell fractionation of rabbit proximal tubules revealed that FBP distributed into two modes: 50% of FBP distributed with alanylaminopeptidase activity (brush border), and the remaining FBP distributed with organelles of lower density that did not show a large digitonin-induced shift to greater density. Infusion of [3H]folate into the kidney followed by isolation and fractionation of the proximal tubules revealed a time-dependent shift of [3H]folate from the heavy (brush border) mode to the lighter organelle mode. By EM immunocytochemistry, rat kidney FBP locates in the brush border, endocytic invaginations, endocytic vacuoles, and dense apical tubules of proximal tubule cells. EM autoradiography of rat kidney 10 min after intravenous infusion of [3H]folate revealed that the label was significantly concentrated only in the brush border, endocytic vesicles, and lysosomes. These data support a mechanism of receptor-mediated endocytosis for the process of FBP-mediated folate transport in the kidney.

scholarly journals Identification and properties of renal mineralocorticoid receptors in relation to glucocorticoid binders in rat liver and kidney

1976 ◽  
Vol 154 (3) ◽  
pp. 567-575 ◽  
Author(s):  
M K Agarwal
Keyword(s):  
Molecular Weight ◽  
Blood Serum ◽  
High Molecular Weight ◽  
Rat Liver ◽  
Rat Kidney ◽  
Deae Cellulose ◽  
Competitive Binding ◽  
Mineralocorticoid Receptors ◽  
Liver And Kidney

The binding of the natural mineralocorticoid aldosterone and the glucocorticoid corticosterone to macromolecules in rat liver and kidney cytoplasmic fractions was compared by various chromatographic procedures. Equilibration of kidney cytosol with 10nM-aldosterone, either alone or in the presence of a competing steroid, was ideal for ionexchange chromatography of DEAE-cellulose DE-52, and revealed the presence of four sorts of binding components. One of these, eluted in the 0.001M-phosphate pre-wash, and another, less abundant, forming a peak at 0.006M-phosphate, did not bind corticosterone at equimolar concentrations, and appear to constitute the mineralocorticoid-specific ‘MR‘ receptor in rat kidney. They could not be detected in the liver. Radioactivity eluted in the 0.02 and 0.06M-phosphate regions on DEAE-cellulose DE-52 appears to be due to [3H]aldosterone binding to glucocorticoid-specific ‘GR’ receptors and to transcortin respectively, since labelling was greater with corticosterone even at 10 nM than with the mineralocorticoid at 100nM and since [14C]corticosterone bound to blood serum transcortin was always co-chromatographed in the 0.06M-phosphate region. These two components appear to be identical with those in the liver and could be labelled maximally only by 100nM-corticosterone. The separation between specific mineralo- and glucocorticoid-binding species was less clear when chromatography was attempted on DEAE-Sephadex A-50 columns, possibly because of disaggregation into subunits in the presence of the high KC1 concentrations required for elution. Competitive binding followed by filtration through Sephadex G-200 gel indicated that cellular MR binders, unlike GR receptors, exist mostly as high-molecular-weight aggregates, although both appear to exhibit a comparable monomeric molecular weight of approx. 67000.

Sign in / Sign up

Export Citation Format

Share Document