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

      Thyroxine-Induced Hyperthyroidism upon the Reproductive Performance of Female Rats

      ,

      Hormone Research in Paediatrics

      S. Karger AG

      Thyroxine, Hyperthyroidism, Mammary growth, Lactation, Reproduction, Rat, DNA, RNA

      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

          L-Thyroxine (L-T<sub>4</sub>) was injected into mature rats daily at levels of 0, 3, 6, 12, 24, 48 and 96 µg/100 g body weight through estrous cycling, conception, pregnancy, parturition and 20 days of lactation. Mothers which lactated to 20 days were killed and mammary glands measured for DNA and RNA content. Those which were not able to maintain their pups were killed on the day when all pups died. Estrous cycling and pregnancy were not markedly effected by exogenous L-T<sub>4</sub> at levels 3–96 times the normal thyroxine secretion rate in rats. After parturition the mothers on L-T<sub>4</sub> above 12 µg did not allow the pups to suckle. As a result the pups died within 2–7 days after birth. Levels of L-T<sub>4</sub> from 3 to 12 µg allowed lactation to progress, but survival of pups to day 20 of lactation was significantly lower than in the normal control group. The results of this study indicate that high levels of L-T<sub>4</sub> inhibit mammary growth and milk secretion. This, in turn, results in the loss of pups, probably through depletion of prolactin as a result of higher metabolic rate due to hyperthyroidism.

          Related collections

          Author and article information

          Journal
          HRE
          Horm Res Paediatr
          10.1159/issn.1663-2818
          Hormone Research in Paediatrics
          S. Karger AG
          1663-2818
          1663-2826
          1975
          1975
          21 November 2008
          : 6
          : 2
          : 85-94
          Affiliations
          Animal Science Research Center and Department of Dairy Husbandry, University of Missouri, Columbia, Mo.
          Article
          178666 Horm Res 1975;6:85–94
          10.1159/000178666
          1183934
          © 1975 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: 10
          Categories
          Paper

          Comments

          Comment on this article