+1 Recommend
1 collections
      • Record: found
      • Abstract: found
      • Article: found

      Mechanism of Corticotropin Action on Adrenal Protein Synthesis

      Read this article at

          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.


          We have recently shown that beside a general stimulation of most adrenal proteins, corticotropin induces a marked increase in a specific adrenal cytosolic protein, protein E. in intact and hypophysectomized rats. To further clarify the mechanisms by which corticotropin exerts its trophic action we have investigated the effects of cycloheximide, calcium and calcium chelator administration on intact and hypophysectomized animals. These substances were injected in rats with or without corticotropin, and slices of adrenal glands from control and treated animals were removed 5 h later, incubated with [<sup>14</sup>C]- or [<sup>3</sup>H]-leucine for 2 h, and cytosolic proteins analyzed by polyacrylamide gel electrophoresis using a dual labelling technique. When high doses of cycloheximide (higher than 500 µg) were injected in rats, incorporation of labelled leucine in adrenal slices of control and corticotropin-treated animals was inhibited. With 500 µg cycloheximide per rat, incorporation of labelled leucine in adrenal slices of control animals was normal, but the corticotropin stimulation of both protein E and total protein synthesis was inhibited. Lower doses of cycloheximide (100 µg per rat) completely inhibited the stimulatory effect of corticotropin on total protein synthesis but did not affect protein E synthesis, while after 50 µg per rat both stimulatory effects were preserved. The two higher doses of cycloheximide (500 and 100 µg per rat) could not completely block the steroidogenic effect of the hormone. The effects of calcium and calcium chelators were studied in 1-day hypophysectomized rats. Calcium alone or injected simultaneously with corticotropin has no effect. Calcium chelators injected simultaneously with corticotropin partially inhibited the stimulatory effects of corticotropin on steroidogenesis but totally inhibited stimulation of total protein synthesis, while the stimulation of protein E persisted. Our results show that after corticotropin, stimulation of protein E synthesis correlates better with steroidogenesis than with total protein synthesis.

          Related collections

          Author and article information

          Horm Res Paediatr
          Hormone Research in Paediatrics
          S. Karger AG
          25 November 2008
          : 15
          : 4
          : 270-282
          Unité de Recherches sur le Contrôle Hormonal des Activités Cellulaires, Inserm U 162, Hôpital Debrousse, Lyon, France
          179466 Horm Res 1981;15:270–282
          © 1981 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
          Pages: 13
          Original Paper


          Comment on this article