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

      Decrease of the Number of Opioid Receptors and of the Responsiveness to Morphineduring Neuronal Differentiation Induced by 17β-Estradiol in Estrogen Receptor-Transfected Neuroblastoma Cells (SK-ER3)

      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

          Estrogens modulate the density of opioid receptors in selected brain areas; however, it is not clear whether they exert such an effect directly on the cells which express the opioid receptors. Therefore, we analyzed the binding of [<sup>3</sup>H]-diprenorphine in human neuroblastoma cells stably transfected with the estrogen receptor cDNA (SK-ER3 cell line). A 16-hour exposure of these cells with 1 nM 17β-estradiol induces a progressive morphological differentiation which appears clearly established 6 days after the suspension of the treatment. The binding of [<sup>3</sup>H]-diprenorphine was then measured immediately after the exposure to 17β-estradiol (16 h) as well as 6 days later. The results shows that the number of opioid receptors in SK-ER3 cells is unaffected at 16 h but appears significantly reduced at 6 days. This effect is blocked by the estrogen antagonist ICI-182780, and is coincident to a decrease of the inhibitory effect of morphine on cyclic AMP accumulation. Binding experiments performed using selective ligands suggest that the µ subclass of opioid receptors is down-regulated by estradiol in SK-ER3 cells.

          Related collections

          Most cited references 8

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

          Sex differences in the antagonism of swim stress-induced analgesia: effects of gonadectomy and estrogen replacement

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

            Effects of steroids on the brain opioid system.

            The experiments reported here add further evidence in support of the view that sex steroids may influence the binding characteristics of brain opioid receptors. In particular, it has been shown that: (a) the number of mu-opioid receptors varies in the hypothalamus of regularly cycling female rats according to the different phases of the estrous cycle, which are characterized by fluctuations of circulating levels of sex steroids; (b) the number of mu-opioid receptors decreases in the hypothalamus and in the corpus striatum when ovariectomized rats are submitted to treatments with estradiol and progesterone able to induce a "positive" feedback effect on LH release. A treatment with estrogen alone able to induce a "negative" feedback effect on LH release brings about an increase of the number of mu-opioid receptors in the thalamus and in the hippocampus; (c) in addition to the mu-receptors, receptors of the delta type may also be involved in the control of gonadotropin secretion; recent results here presented indicate that a line of immortalized hypothalamic cells (GT1 cells), which synthesize and secrete LHRH, present delta opioid receptors on their membranes; these are apparently involved in the control of LHRH release from these cells.
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              Minireview: Multiple MU opiate receptors

                Bookmark

                Author and article information

                Journal
                NEN
                Neuroendocrinology
                10.1159/issn.0028-3835
                Neuroendocrinology
                S. Karger AG
                0028-3835
                1423-0194
                1999
                January 1999
                27 January 1999
                : 69
                : 1
                : 54-62
                Affiliations
                aDepartment of Endocrinology and bMilano Molecular Pharmacology Laboratory, Institute of Pharmacological Sciences, University of Milan, Italy
                Article
                54403 Neuroendocrinology 1999;69:54–62
                10.1159/000054403
                9892851
                © 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: 4, Tables: 2, References: 48, Pages: 9
                Categories
                Differentiating Effects and Localization ofEstrogen Receptors

                Comments

                Comment on this article