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      Simultaneous Inhibition of Renal Phospholipase A 2 and Glutathione Synthesis by Manoalide and DL-Buthionine Sulfoximine Induces Acute Tubular Dysfunction in Rats

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          Abstract

          We have previously demonstrated that gentamicin-induced acute renal failure is mediated by the consumption of renal glutathione (GSH) and accumulation of oxidized phospholipids in tubular epithelial cells as a result of inhibition of phospholipase A<sub>2</sub> (PLA<sub>2</sub>) activity. Based on these results, we tested the hypothesis that the simultaneous inhibition of PLA<sub>2</sub> and GSH synthesis induces acute renal failure similar in characteristics to gentamicin-induced acute renal failure. Male Sprague-Dawley rats kept under standard laboratory conditions were administered 3 mmol/kg of DL-buthionine sulfoximine (BSO; γ-glutamylcysteine synthetase inhibitor) and 30 μg/kg of manoalide (PLA<sub>2</sub> inhibitor), following which significant elevations in serum creatinine and urinary lysosomal enzyme levels (elevation of N-acetyl-β- D-glucosaminidase activity) were observed. The renal tissue GSH content was reduced in the group that received both BSO and manoalide as compared with the group that received manoalide alone. The renal tissue GSH content was also reduced in the group that received BSO alone. The renal tissue concentration of 2-thiobarbituric-acid-reactive substances increased rapidly, followed by an increase in renal tissue total phospholipid concentration in the group that received both BSO and manoalide. In contrast, the activity of PLA<sub>2</sub> in renal tissue decreased in the group that received both BSO and manoalide as compared with the groups that received BSO alone or physiological saline. In conclusion, concomitant administration of BSO and manoalide induces renal tubular damage and acute renal failure in rats, similar in characteristics to gentamicin-induced nephrotoxicity, whereas administration of BSO or manoalide alone did not. These results suggest that both inhibition of PLA<sub>2</sub> and GSH depletion are necessary for the induction of acute renal failure.

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          Most cited references 3

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          Manoalide, an antibiotic sesterterpenoid from the marine sponge (polejaeff)

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            Establishment of a Hydrogen Peroxide Resistant Variant of Renal Tubular Epithelial Cells: Role of Calcium-Independent Phospholipase A2 in Cell Damage

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              Biochemical Renal Manifestations Induced by Consecutive Administration of Gentamicin in Rats

              In the present study, we investigated the generation of lipid peroxides and changes in total phospholipid levels in the kidney tissue of rats with acquired resistance to gentamicin (GM). GM resistance was induced in Sprague-Dawley male rats by subcutaneously administering each rat a dose of 80 mg/kg/day of GM for 40 consecutive days. Twelve days after the GM administration, serum urea nitrogen peaked at 35 mg/dl. The urinary creatinine excretion progressively decreased, beginning 4 days after the start of GM administration. The fractional excretion of sodium progressively increased, beginning 4 days after the start of GM administration, peaking on the 10th day. However, despite the continuation of GM administration, the urinary creatinine excretion gradually increased, and the serum urea nitrogen concentrations recovered to previous levels after 21 days. We also analyzed the relationship between the acquired resistance to GM and changes in the reduced glutathione content and glutathione peroxidase activity. Simultaneously, we investigated sequential changes in the activities of phospholipase A 2 and phospholipase C, which release peroxidized membrane phospholipids into the cytoplasm via hydrolysis, as well as the relationship between changes in the kidney tissue phospholipid composition (sphingomyelin/phosphatidylcholine ratio) and renal function. We found that (1) the kidney tissue glutathione content rapidly decreased after GM administration before subsequently increasing and being maintained at a higher level; (2) the glutathione peroxidase activity showed a persistent decrease after GM administration; (3) the kidney tissue phospholipase A 2 activity decreased after GM administration, while the phospholipase C activity exhibited a sustained increase from 21 days, and (4) the spingomyelin/phosphatidylcholine ratio decreased on the 4th day before stabilizing when acquired resistance was obtained. Based on these findings, we conclude that an increased supply of reduced glutathione and the induction of an antioxidase, substituting for glutathione peroxidase, may play a significant role in the acquisition of resistance to acute renal failure which occurs with continuous GM administration. Improved membrane fluidity, achieved by maintenance of the membrane phospholipid composition by increased phospholipase C activity, may be an additional factor contributing to the recovery of the renal function.
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                Author and article information

                Journal
                EXN
                Nephron Exp Nephrol
                10.1159/issn.1660-2129
                Cardiorenal Medicine
                S. Karger AG
                1660-2129
                2000
                April 2000
                15 March 2000
                : 8
                : 2
                : 84-90
                Affiliations
                1st Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan
                Article
                20653 Exp Nephrol 2000;8:84–90
                10.1159/000020653
                10729747
                © 2000 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: 3, Tables: 2, References: 26, Pages: 7
                Product
                Self URI (application/pdf): https://www.karger.com/Article/Pdf/20653
                Categories
                Original Paper

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