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

      L-Dopa Effects on Serum LH and Prolactin in Old and Young Female Rats

      , , ,


      S. Karger AG

      L-dopa, Serum LH, Prolactin, Aging

      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.


          Serum LH and prolactin changes in response to an acute systemic L-dopa injection were measured in young (4–6 months) proestrous, estrous and 2nd day diestrous rats, and in aged (23–30 months) constant estrous and pseudopregnant (long diestrous) Long-Evans rats. Serum LH and prolactin were measured by radioimmunoassays in serial blood samples taken before and 15, 60 and 120 min after i.p. injections of 0, 3 or 30 mg of L-dopa. Pretreatment serum prolactin levels were elevated in afternoon samples from young proestrous and estrous rats and in both aged groups. Both the 3- and 30-mg injections caused a reduction in serum prolactin in all groups. The reduction in serum prolactin following 3 mg of L-dopa was less in both the aged groups than in the young rats. The pretreatment serum LH concentration was markedly elevated only on the afternoon of proestrus. The pretreatment serum LH level of the aged constant estrous group was greater than that of either the young estrous or diestrous group. Pretreatment serum LH levels were lower in aged pseudopregnant rats than in young diestrous rats. After the 30-mg L-dopa injection serum LH increased in all groups except the aged pseudopregnant group. Although the increase in LH following L-dopa injection was similar in young estrous and aged constant estrous rats, the increase in serum LH occurred later and lasted longer in the latter group. These data indicate that the hypothalamic-anterior pituitary endocrine control mechanisms are less responsive to acute L-dopa treatment in the aging female rat.

          Related collections

          Author and article information

          S. Karger AG
          20 March 2008
          : 19
          : 4
          : 331-338
          Endocrine Research Unit, Departments of Physiology and Animal Husbandry, Michigan State University, East Lansing, Mich.
          122454 Neuroendocrinology 1975;19:331–338
          © 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: 8


          Comment on this article