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

      Lack of Evidence for Acute Effects of Growth Hormone-Releasing Hormone on Serum Insulin and Glucose Levels in Normal and Hypophysectomized Rats

      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.


          Growth hormone (GH) is diabetogenic but has also been suggested to stimulate insulin release. Our aim was to study whether acute effects of GH on serum insulin and glucose concentrations can be observed when GH release is physiologically induced by GH-releasing hormone (GHRH), which is known to stimulate insulin secretion. We also studied the acute effects of GHRH as such on insulin release in vivo and in vitro. Female Sprague-Dawley rats were hypophysectomized (hypox) at 40 days of age. At day 188, rats received 1 μg GHRH( 1-29)/100 g body weight i.v. In sham-operated rats, GHRH induced a rise in serum GH from 36.5 ± 1.9 ng/ml (time 0 min) to 560.0 ± 13.3 ng/ml (5 min;) (n = 6; p < 0.001). In hypox rats, no measurable serum levels of GH were detected either before or after GHRH treatment. Serum insulin was unaffected by GHRH in both groups of animals. Serum glucose was higher in sham operated than in hypox rats (7.3 ± 0.4 vs. 6.3 ± 0.1 mM at 0 min; p < 0.01). Serum glucose did not rise following GHRH injection. In isolated rat islets, cultured for 3 days at 11.1 m M glucose, 0.1-10 n M GHRH stimulated basal insulin release at 3 m M glucose. To summarize, GHRH at high concentrations stimulates insulin release in vitro, but neither GHRH, at a concentration where GH secretion is greatly stimulated, nor GHRH-induced GH release, have any acute effects on serum insulin or glucose levels.

          Related collections

          Author and article information

          Horm Res Paediatr
          Hormone Research in Paediatrics
          S. Karger AG
          05 December 2008
          : 41
          : 1
          : 21-26
          Department of Histology and Cell Biology, University of Umeå, Sweden
          183872 Horm Res 1994;41:21–26
          © 1994 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