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

      Relationship between Rhythmic Motor Activity and Plasma Luteinizing Hormone in Ovariectomized Sheep



      S. Karger AG

      Luteinizing hormone, Rest-activity cycle, Ultradian rhythm, Ovariectomy

      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.


          The timing of the episodic secretion of luteinizing hormone (LH) in ovariectomized ewes was investigated with respect to an ultradian rest-activity cycle. Individual sheep were enclosed in a chamber where their physical activity was continuously monitored, and blood samples for LH analysis were collected at 5-min intervals through a cannula extending to the exterior of the chamber. Concurrent profiles of motor activity and plasma LH during 5-hour sampling trials were each analyzed for rhythmicity by power spectral analysis. Temporal relationships between rhythms in motor activity and plasma LH were examined by cross-spectral analysis. Both activity and plasma LH levels tended to fluctuate rhythmically, and the occurrences of rhythmicity for LH and for activity were correlated. The periods (reciprocal of frequencies) for the LH rhythms and activity rhythms were highly correlated within individual trials, and across trials they both averaged 36 min. Cross-spectral analysis indicated that plasma LH tended to be elevated during times of either greatest or least motor activity. These results suggest a relationship between the rhythmic secretion of LH and the rest-activity cycle which may be based on a mechanism of independent entrainment to a common timing rhythm.

          Related collections

          Author and article information

          S. Karger AG
          26 March 2008
          : 32
          : 6
          : 364-369
          Department of Animal Sciences, Purdue University, West Lafayette, Ind., USA
          123187 Neuroendocrinology 1981;32:364–369
          © 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: 6
          Original Paper


          Comment on this article