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

      Centrally Administered Murine Leptin Stimulates Plasma Arginine-Vasopressin Secretion and Increases the Level of mRNA Expression in the Supraoptic Nucleus of Conscious Rats

      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

          The product of the ob gene protein, leptin, has been suggested to function as an endogenous mediator of the cardiovascular system via sympathetic nerve activity. Moreover, extensive distribution of leptin receptor-like immunoreactivity has been demonstrated in the choroid plexus, cerebral cortex, hippocampus, thalamus and hypothalamus, especially in the paraventricular nucleus (PVN) and supraoptic nucleus (SON). In this study, we have investigated the in vivo effects of leptin on plasma arginine-vasopressin (AVP) secretion and the level of AVP messenger ribonucleotic acid (AVP mRNA) in the SON of conscious rats. Intracerebroventricularly administered leptin increased plasma AVP concentration in a dose-dependent manner (0–400 pmol/rat). The maximal effect was obtained at 15 min after the administration of leptin. Furthermore, in Northern blot analyses, the levels of AVP mRNa in the SON increased approximately 2-fold from the basal level after the administration of leptin. AVP mRNA expression in the PVN was also increased by leptin. However, leptin had no effects on plasma oxytocin (OXT) secretion and OXT gene expression in the SON. In conclusion, leptin is involved in AVP secretion via the central nervous system, however, its physiological role is unknown.

          Related collections

          Most cited references 9

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

          Abnormal splicing of the leptin receptor in diabetic mice.

          Mutations in the mouse diabetes (db) gene result in obesity and diabetes in a syndrome resembling morbid human obesity. Previous data suggest that the db gene encodes the receptor for the obese (ob) gene product, leptin. A leptin receptor was recently cloned from choroid plexus and shown to map to the same 6-cM interval on mouse chromosome 4 as db. This receptor maps to the same 300-kilobase interval as db, and has at least six alternatively spliced forms. One of these splice variants is expressed at a high level in the hypothalamus, and is abnormally spliced in C57BL/Ks db/db mice. The mutant protein is missing the cytoplasmic region, and is likely to be defective in signal transduction. This suggests that the weight-reducing effects of leptin may be mediated by signal transduction through a leptin receptor in the hypothalamus.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            The role of neuropeptide Y in the antiobesity action of the obese gene product.

            Recently Zhang et al. cloned a gene that is expressed only in adipose tissue of the mouse. The obese phenotype of the ob/ob mouse is linked to a mutation in the obese gene that results in expression of a truncated inactive protein. Human and rat homologues for this gene are known. Previous experiments predict such a hormone to have a hypothalamic target. Hypothalamic neuropeptide Y stimulates food intake, decreases thermogenesis, and increases plasma insulin and corticosterone levels making it a potential target. Here we express the obese protein in Escherichia coli and find that it suppresses food intake and decreases body weight dramatically when administered to normal and ob/ob mice but not db/db (diabetic) mice, which are thought to lack the appropriate receptor. High-affinity binding was detected in the rat hypothalamus. One mechanism by which this protein regulated food intake and metabolism was inhibition of neuropeptide-Y synthesis and release.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Design and synthesis of multi-haem proteins.

              A water-soluble, 62-residue, di-alpha-helical peptide has been synthesized which accommodates two bis-histidyl haem groups. The peptide assembles into a four-helix dimer with 2-fold symmetry and four parallel haems that closely resemble native haems in their spectral and electrochemical properties, including haem-haem redox interaction. This protein is an essential intermediate in the synthesis of molecular 'maquettes', a novel class of simplified versions of the metalloproteins involved in redox catalysis and in energy conversion in respiratory and photosynthetic electron transfer.
                Bookmark

                Author and article information

                Journal
                NEN
                Neuroendocrinology
                10.1159/issn.0028-3835
                Neuroendocrinology
                S. Karger AG
                0028-3835
                1423-0194
                1999
                September 1999
                15 September 1999
                : 70
                : 3
                : 207-212
                Affiliations
                aFirst Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, and bDepartment of Physiology, Miyazaki Medical College, Miyazaki-gun, Japan
                Article
                54478 Neuroendocrinology 1999;70:207–212
                10.1159/000054478
                10516484
                © 1999 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: 1, References: 34, Pages: 6
                Categories
                Neuroendocrine Effects of Leptin

                Comments

                Comment on this article