Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To identify the structural change coincident with increased glomerular permeability in both adriamycin (ADR) and puromycin-aminonucleoside (PAN) nephrosis, we explored the temporal correlation between developing proteinuria, the reduction in glomerular polyanions, and the detachment of epithelium from glomerular basement membrane (GBM). Sprague-Dawley rats received a single tail-vein injection of PAN (150 mg/kg), ADR (7.5 mg/kg) or saline. Nephrotic-range proteinuria appeared between days 2 to 5 in the PAN-treated and days 5 to 10 in the ADR-treated rats. The GBM heparan sulfate charge density and epithelial membrane sialic acid (SA) content were determined before, during and after the rise in proteinuria. Polyethyleneimine was used to detect heparan sulfate and the number staining of renal cortical slices was used to detect heparin sulfate and the number of sites/microns GBM in the lamina rara externa were counted on electron micrographs (magnification x60,000). Controls had a regular distribution of polyethyleneimine 20.19 +/- 1.72 sites/microns (X + SD). In ADR rats, the polyethyleneimine density decreased by day 5, 18.61 +/- 1.79 sites/microns (p less than 0.05) which persisted to day 15, 17.38 +/- 1.27 sites/microns (p less than 0.02). PAN rats, by day 1, had significant reduction, 14.94 +/- 1.47 sites/microns (p less than 0.05), which persisted to day 20. The total membrane-bound SA content of isolated glomeruli was analyzed with a modified Warren's method. The SA content in control glomeruli was 46.8 +/- 8.0 nmol/mg glomerular protein (X +/- SD). In ADR rats, there was significant decrease in SA content to 84 +/- 3% of control (p less than 0.01) at day 15. In PAN rats, by day 2, the SA content was decreased to 73 +/- 18% of control (p less than 0.05). In both models, scanning and transmission electron microscopy revealed epithelial foot process fusion, loss of slit diaphragms, and vacuolization before increased proteinuria. Epithelial detachment from the GBM and rupture of vacuoles occurred coincidently with rapid development of nephrotic proteinuria in both models. In summary, reduced GBM heparan sulfate and epithelial SA content do not correlate with the onset of altered glomerular permeability, whereas epithelial detachment is coincident with the development of massive proteinuria in both ADR and PAN nephrosis.
 ...
PMID:Glomerular epithelial detachment, not reduced charge density, correlates with proteinuria in adriamycin and puromycin nephrosis. 260 Dec 99

We have previously described a significant increase in 35sulfate uptake in rat glomerular basement membrane (GBM) when glomeruli were cocultured with peripheral blood mononuclear cells (PBMC) from patients with idiopathic minimal-lesion nephrotic syndrome (IMLNS) in relapse, but not with PBMC of IMLNS patients in remission. In the present study we examined the effect of prednisone therapy on the PBMC-mediated increase in 35sulfate GBM uptake. The GBM 35sulfate uptake after rat glomeruli were cocultured with PBMC from 11 IMLNS patients in relapse (geometric mean 437 cpm/mg dry glomerular weight) was significantly higher than the incorporation observed in glomeruli cultured alone (geometric mean 229 cpm/mg dry glomerular weight; p less than 0.01). However, no significant differences in 35sulfate uptake were seen between glomeruli cultured alone and glomeruli cocultured with PBMC from IMLNS patients when PBMC were obtained from the 11 patients on treatment with prednisone (2 mg/kg/day) or the same patients in remission and off prednisone therapy. Prednisone therapy abolished the PBMC-mediated increased 35sulfate uptake by rat GBM. GBM sulfated compounds seem to play a role in glomerular permeability. The temporal relationship between inhibition of GBM sulfate incorporation by prednisone and resolution of the proteinuria support the hypothesis that PBMC from IMLNS patients in relapse could secrete a lymphokine which by altering the metabolism of the GBM sulfated compounds may subsequently increase glomerular permeability to plasma proteins.
 ...
PMID:Effect of prednisone on nephrotic peripheral blood mononuclear cell mediated increase in 35sulfate uptake in rat glomerular basement membrane. 279 47

We investigated nephritogenic potential of antibodies to heparan sulfate-proteoglycan of glomerular basement membrane. Glomeruli were isolated, basement membranes were prepared, proteoglycans extracted, and purified core protein was obtained. We immunized rabbits with the core protein, IgG fraction prepared from the antisera and specificity of the antibody determined. A single immunoprecipitin line in agar diffusion plate and a single band (approximately 18,000 mol wt) on the immunoblot autoradiograms were visualized. The antibody showed precise reactivity with the glomerular basement membranes. The clearance studies indicated that approximately 75% of the radioiodinated antibody disappeared from circulation within 1 h and 1-2% bound to the kidney. For nephritogenicity experiments, the antibody was intravenously administered into rats and we examined their kidneys at 1 h to 24 d later. A linear immunofluorescence of glomerular basement membranes was observed with rabbit IgG at all times while that of C3 until the 10th day. Early morphologic changes included glomerular infiltration of polymorphonuclear leukocytes with focal exfoliation of endothelium. The leukocytic infiltration subsided by the third day and was followed by progressive thickening of basement membranes, focal mesangial cell proliferation, increase in mesangial matrix, and accumulation of monocytes. Focal knob-like thickening of glomerular basement membrane was observed from the 15th day onward. Regularly-spaced electrondense deposits were seen in the lamina rara interna and externa of glomerular basement membranes and persisted throughout the investigatory period. No significant proteinuria was observed at any stage of the experiment. These findings suggest that the antibodies to the basement membrane heparan sulfate-proteoglycan are nephrotoxic but possess weak nephritogenic potential.
 ...
PMID:Nephritogenicity of antibodies to proteoglycans of the glomerular basement membrane--I. 293 58

In vivo studies in rats demonstrated that the binding of a highly cationic antigen (cationized human IgG, pI greater than 9.5) to glomerular polyanion could be significantly reduced by prior application of a small polycation, protamine sulfate. The degree of inhibition was dose dependent and the highest dose used, 4 mg/100 g body weight, reduced antigen binding by approximately 70%. In further experiments the ability of protamine sulfate to enhance elimination of cationic antigen-antibody immune complexes from the glomerular capillary wall was examined. Daily treatment with protamine sulfate, starting after induction of nephritis, produced a significant but only moderate reduction in the persistence of the antigen, without having any effect on proteinuria. Proteinuria could only be prevented when protamine sulfate was given immediately before induction of nephritis. Protamine sulfate had little influence on the course of established renal disease in the model employed. These results do not substantiate the concept of charge competition as a potentially useful therapeutic strategy.
 ...
PMID:The effect of protamine sulfate on the course of immune complex glomerulonephritis in the rat. 294 40

20 healthy children, 20 children with tubulointerstitial nephritis (TIN) and 20 children with glomerulonephritis in the active state were examined. Polyacrylamide gel electrophoresis of urinary proteins, beta-2-microglobulin excretion and acid glycosaminoglycan electrophoresis were performed. Polyacrylamide-gel electrophoresis showed in all the cases with TIN low molecular weight proteinuria, no bands were observed in healthy children and in all the cases of glomerulonephritis high molecular weight proteinuria. Beta-2-microglobulin determination showed no differences between healthy children and children with glomerulonephritis, but showed high levels in the group of children with TIN. Acid glycosaminoglycan electrophoresis showed in the group of children with healthy children a mean chondroitin-4-sulfate-/heparan sulfate ratio (CS/HS) of 3.8 +/- 0.4. Children with TIN presented a low ratio of 1.5 +/- 0.5. Patients with glomerulonephritis showed a mean ratio of 3.7 +/- 0.3. Our results clearly show that tubular damage can be revealed by a low quotient of chondroitin-4-sulfate to heparan sulfate.
 ...
PMID:Noninvasive diagnosis of tubular damage by the use of the urinary chondroitin-4-sulfate/heparan sulfate ratio. 295 42

To investigate the role of antibody to heparan sulfate (HS) in the development of glomerular injury, male Lewis rats were immunized with HS and compared with unimmunized controls. In HS-immunized rats circulating antibodies that bound to renal basement membranes, an increase in serum creatinine (0.8 mg/dl versus 0.6 in controls P less than 0.01), and a 40% decline in creatinine clearance developed. In no animal did abnormal proteinuria develop. By histologic examination there was glomerular and interstitial capillary engorgement with erythrocytes, modest infiltration by polymorphonuclear leukocytes, and no proliferation of intrinsic glomerular cells. Immunofluorescence microscopy demonstrated deposits of rat IgG along the glomerular basement membrane. Bowman's capsule, and peritubular capillaries. Electron-microscopic examination revealed capillary engorgement with erythrocytes that appeared adherent to each other and contained entrapped areas of rarefied material. These observations demonstrate that binding of antibody to HS in the glomerulus induces a mild inflammatory reaction and a reduction in glomerular filtration rate, but no abnormal proteinuria.
 ...
PMID:Characterization of renal injury initiated by immunization of rats with heparan sulfate. 296 3

Antibodies to glomerular basement membrane, heparan sulfate-proteoglycans are nephrotoxic but possess a weak nephritogenic potential. In order to enhance the nephritogenic potential, the antibodies were intravenously administered into rats presensitized with heterologous rabbit IgG. This resulted in the integration of heterologous and autologous phases, the two phases characteristic of the traditional model of nephrotoxic serum nephritis. The presensitization caused a dramatic shift in the binding characteristics of the heterologous antibodies between the kidney and lymphoid tissues. A proliferative form of immune complex glomerulonephritis associated with a remarkable proteinuric response was observed. In addition, a moderate degree of hematuria was noted as well. The proteinuria was largely complement-dependent and may possibly be cell-mediated as well. The proteinuria became severe with increasing production of host IgG antibodies and with their subsequent sequestration in the glomeruli. The predominant glomerular lesions were in the form of epimembranous/subepithelial immune deposits, which became more frequent with timely increasing titer of host autologous IgG antibodies. These findings indicate that antibodies to heparan sulfate-proteoglycan, an authentic component of the basement membrane, are capable of mediating a glomerular injury with acquisition of nephritogenic potential in an appropriate environment of the host. At present, it seems that this is the sole constituent of the basement membrane whose antibodies are capable of inducing an immune complex nephritis.
 ...
PMID:Nephritogenicity of proteoglycans. II. A model of immune complex nephritis. 297 59

Proteinuria in aminonucleoside of puromycin (PAN) nephrosis is due to an alteration of the glomerular charge- and size-selective barrier. Heparan sulfate seems to play a role in glomerular charge permeability to plasma proteins. We report a quantitative analysis and metabolism of glomerular basement membrane (GBM) heparan sulfate in PAN nephrosis. Studies were performed 5 and 10 days post-PAN administration (15 mg/100 g) to Sprague-Dawley rats. GBM heparan sulfate glycosaminoglycan was measured using the dimethylmethylene blue test after chromatographic separation of the digested GBM. Sulfate-35 uptake by GBM and catabolism of GBM-sulfated compounds were studied using glomerular cultures. The heparan sulfate glycosaminoglycans concentration on day 5 (1.42 micrograms/mg GBM protein) was within the normal range (1.17 +/- 0.25), but the concentration on day 10 was below the limit of detection (0.57 micrograms/mg). The sulfate-35 incorporated in the GBM glycosaminoglycan on day 5 (158 cpm/micrograms glycosaminoglycan) was lower than the uptake of control GBM (270 cpm/micrograms glycosaminoglycan), and markedly lower than the uptake on day 10 (1,590 cpm/micrograms glycosaminoglycan). The catabolism of the GBM sulfated compounds on day 5 and 10 was not different than the one seen in controls. These data suggest that PAN administration is associated with a decrease in synthesis of GBM-sulfated compounds on day 5 and a decrease in GBM heparan sulfate glycosaminoglycan on day 10. However, on day 10, an increased compensatory synthesis is observed. This may subsequently normalize the GBM heparan sulfate concentration and explain the resolution of the proteinuria.
 ...
PMID:Glomerular basement membrane heparan sulfate glycosaminoglycan in aminonucleoside of puromycin nephrosis. 297 21

The Coomassie Brilliant Blue G-250 method for urinary proteins underestimates urinary immunoglobulin light chains when albumin or pooled serum is used as the protein standard. The specific color yields of these and other proteins can be brought closer together by adding sodium dodecyl sulfate to the reagent; however, there is some loss of sensitivity. We found such a reagent to be satisfactory for assaying urinary proteins on studying 43 patients with light-chain proteinuria, 19 of whom had multiple myeloma and six possible multiple myeloma.
 ...
PMID:Improved measurement of urinary total protein (including light-chain proteins) with a Coomassie brilliant blue G-250-sodium dodecyl sulfate reagent. 311 57

Urinary protein excreted in active in situ immune complex glomerulonephritis (ICGN) was qualitatively analyzed by the comparison of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of urinary proteins from rats with Masugi GN, active Heymann GN (AHGN), and chronic serum sickness GN (CSSGN). In the SDS-PAGE analysis of urinary protein excreted in the active in situ ICGN and Masugi GN models, 200- and 145-kD macromolecules and low molecular weight components around 12 kD were excreted in large quantities at the full development stage (greater than 100 mg/24 h urinary protein). These findings, however, were obscure or lacking in CSS-GN and AHGN at the peak of proteinuria. Electrophoretic patterns of urinary proteins including lower molecular weight proteins could be divided into two groups: either active in situ ICGN and Masugi GN or AHGN and CSSGN. These two groups corresponded to the differences of morphologic expression such as proliferative changes rather than degree of proteinuria. The location of immune complex formation and deposition, probably different among the experimental models, may play an important role for determining the mediation and nature of glomerular injury.
 ...
PMID:The electrophoretic pattern of urinary protein in in situ immune complex glomerulonephritis. 326 89


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>