Blog
About

4
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      Nephrotic-Like Proteinuria in Experimental Diabetes

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Aims/Hypothesis: Streptozotocin (STZ) diabetic rats are characterized by the development of albuminuria. It is not known, however, whether the excess excretion of protein is primarily due to intact protein or protein fragments or whether it is specific for albumin or occurs for all high-molecular-weight plasma proteins. To test this we have measured the excretion rates and fractional clearances of [<sup>14</sup>C]albumin, [<sup>3</sup>H]immunoglobulin G and [<sup>3</sup>H]transferrin in diabetic rats. Methods: The radiolabeled proteins were delivered to the circulation of conscious diabetic (STZ induced for 6 weeks) and control rats by ALZET osmotic pumps. The plasma level of the radiolabeled proteins reached steady-state levels by day 7. Urine and plasma samples from day 7 were used to determine the excretion rates of the proteins by radioactivity and radioimmunoassay. Results: When excretion rates were determined by radioactivity it was apparent that only the albumin excretion rate increased significantly with STZ diabetes to a value of 354 ± 166 µg/min which agrees with proteinuria determined by Biuret assay of 299.9 ± 52.4 µg/min. The major proportion of protein being excreted was in the form of protein fragments which are not detected by conventional immmunochemical assays. Conclusion: The previously unrecognized nephrotic-like levels of proteinuria in experimental diabetes appears to be associated with an albumin-specific mechanism responsible for the increase in albumin peptides in urine. There was significant lowering of plasma albumin concentration but plasma concentrations of transferrin and immunoglobulin G remained unchanged. There was also no significant appearance of intact protein in urine that is normally found in nephrotic states.

          Related collections

          Most cited references 4

          • Record: found
          • Abstract: found
          • Article: not found

          Renal handling of albumin: a critical review of basic concepts and perspective.

          Biochemical and physiological processes that underlie the mechanism of albuminuria are completely reassessed in this article in view of recent discoveries that filtered proteins undergo rapid degradation during renal passage and the resulting excreted peptide fragments are not detected by conventional urine protein assays. This means that filtered protein and/or albumin levels in urine have been seriously underestimated. The concept that albuminuria is a result of changes in glomerular permeability is questioned in light of these findings and also in terms of a critical examination of charge selectivity, shunts, or large-pore formation and hemodynamic effects. The glomerulus appears to function merely in terms of size selectivity alone, and for albumin, this does not change significantly in disease states. Intensive albumin processing by a living kidney occurs through cellular processes distal to the glomerular basement membrane. Failure of this cellular processing primarily leads to albuminuria. This review brings together recent data about urinary albumin clearance and current knowledge of receptors known to process albumin in both health and disease states. We conclude with a discussion of topical and controversial issues associated with the proposed new understanding of renal handling of albumin. Copyright 2002 by the National Kidney Foundation, Inc.
            Bookmark
            • Record: found
            • Abstract: not found
            • Article: not found

            Ramipril and aminoguanidine restore renal lysosomal processing in streptozotocin diabetic rats

              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Production and characterization of [14C]protein A, a long-lived immunological reagent

               Ludeman Eng (1985)
              A procedure for the production of [14C]protein A is described which involves reductive methylation of lysine residues with [14C]formaldehyde and NaCNBH3. The binding of [14C]protein A to IgG is apparently unaltered, as determined by competitive binding studies. The use of [14C]protein A may be preferred to that of 125I-protein A when a radioactive label with a long half-life is desirable.
                Bookmark

                Author and article information

                Journal
                AJN
                Am J Nephrol
                10.1159/issn.0250-8095
                American Journal of Nephrology
                S. Karger AG
                0250-8095
                1421-9670
                2003
                October 2002
                23 October 2002
                : 23
                : 1
                : 38-46
                Affiliations
                aDepartment of Biochemistry and Molecular Biology, Monash University, Clayton and bEndocrine Unit, Austin and Repatriation Medical Center, Heidelberg, Vic., Australia
                Article
                66297 Am J Nephrol 2003;23:38–46
                10.1159/000066297
                12373079
                © 2003 S. Karger AG, Basel

                Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher. Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

                Page count
                Figures: 5, Tables: 5, References: 38, Pages: 9
                Product
                Self URI (application/pdf): https://www.karger.com/Article/Pdf/66297
                Categories
                Original Article: Basic Sciences

                Comments

                Comment on this article