Glucocorticoids are known to decrease growth hormone (GH) secretion in man. Galanin, a 29-amino acid peptide, and arginine stimulate GH secretion through different hypothalamic mechanisms. The aim of our study was to investigate the effect of arginine and galanin (alone or in combination) on GH secretion in 7 adult patients with nonendocrine diseases receiving chronic daily immunosuppressive glucocorticoid treatment (5 F, 2 M; mean age 48.4 ± (SEM) 3.7 years). Five normal adults (3 F, 2 M; mean age 34.6 ± 2.2 years) served as controls. All subjects underwent in random order: (1) infusion of arginine hydrochloride (30 g i.v. in 100 ml saline) from -30 to 0 min; (2) infusion of synthetic porcine galanin (500 µg i.v. in 100 ml saline) from -15 to 30 min; (3) intravenous infusion of arginine hydrochloride from -30 to 0 min combined with synthetic porcine galanin from -15 to 30 min. In normal subjects GH peak after arginine (8.6 ± 3.3 µg/1) and galanin (6.6 ± 3.2 µg/1) did not show significant differences; the GH peak after arginine + galanin (21.4 ± 6.1 µg/1) was significantly higher with respect to galanin or arginine alone. In glucocorticoid-treated patients the GH peak after arginine (4.6 ± 1.5 µg/1) was significantly (p < 0.05) higher with respect to galanin (1.8 ± 1.0 µg/1); after arginine + galanin the GH peak (8.2 ± 2.3 µg/1) was significantly (p < 0.05) enhanced with respect to either galanin or arginine alone. The GH response to arginine was not significantly different in normal and glucocorticoid-treated patients. Normal subjects showed higher GH peaks after galanin alone and arginine + galanin with respect to the steroid-treated group. Moreover, we hypothesize that the inhibitory action of glucocorticoids on GH secretion in man is mediated not only by an increase in somatostatin tone but also by a decrease in endogenous hypothalamic GHRH release.

Keywords:
Galanin, Arginine, Glucocorticoids, Growth hormone, Somatostatin, Growth hormone-releasing hormone, Immunosuppression
This content is only available via PDF.
© 1992 S. Karger AG, Basel
1993
Copyright / Drug Dosage / Disclaimer
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.
You do not currently have access to this content.