11
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      Characterization of Cephalic Arteriovenous LH Differences by Continuous Sampling in Ovariectomized Sheep

      research-article

      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

          Blood from the external carotid artery and from the external jugular vein were collected simultaneously, and luteinizing hormone (LH) concentrations were measured in order to determine the temporal pattern of the large episodic pulses of LH secretion which are characteristic of ovariectomized sheep. Collection of paired arterial and venous samples at 5-min intervals did not provide adequate resolution of arteriovenous LH changes which accompany these pulses. Therefore, a continuous blood sampling system was developed which permitted collection of paired arterial and venous samples over 20-second intervals throughout a sampling period of approximately 45 min. One large pulse of LH secretion was detected in 6 of 9 trials, and each pulse was characterized by a brief period (2–6 min) when venous concentrations of LH were much higher than corresponding arterial concentrations. Periods of considerable release of LH from the head were usually followed by a period when arterial LH levels were greater than the venous levels, indicating that LH was being removed from the circulation by the tissues of the head. Administration of synthetic GnRH pulses (17.5–35 ng) through the arterial cannulae of halothane-anesthetized ewes produced in different trials arteriovenous LH concentration differences ranging from no discharge of LH to discharges much larger and more prolonged than those occurring spontaneously in conscious ewes. These results suggest that individual episodes of spontaneous pulsatile discharge of LH in ovariectomized sheep last 2–6 min and probably result from episodic secretion of LH-releasing hormone by the hypothalamus. Profiles of circulating LH also appear to be modified by extravascular sequestration of LH.

          Related collections

          Author and article information

          Journal
          NEN
          Neuroendocrinology
          10.1159/issn.0028-3835
          Neuroendocrinology
          S. Karger AG
          0028-3835
          1423-0194
          1982
          1982
          26 March 2008
          : 34
          : 6
          : 415-420
          Affiliations
          Department of Animal Sciences, Purdue University, West Lafayette, Ind., USA
          Article
          123338 Neuroendocrinology 1982;34:415–420
          10.1159/000123338
          7048124
          e7aa3bbb-2148-47c2-a8af-d285a324fe88
          © 1982 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.

          History
          : 11 May 1981
          : 20 November 1981
          Page count
          Pages: 6
          Categories
          Original Paper

          Endocrinology & Diabetes,Neurology,Nutrition & Dietetics,Sexual medicine,Internal medicine,Pharmacology & Pharmaceutical medicine
          Luteinizing hormone,Hormone equilibration,Ovariectomy,Cephalic arteriovenous differences,Pulsatile secretion

          Comments

          Comment on this article