Background: This study deals with the physiological effects of an oral bolus of essential amino acids (AA) on the secretion of insulin, ghrelin and leptin in fasting humans. Methods: 12 healthy adults (age 18–40 years, 10 males, 2 females, body mass index 18.0–23.5 kg/m2) were included in our study. Seven fasted volunteers consumed an AA mixture (0.35 g/kg BW), 5 served as controls. Serum AA, glucose, albumin, urea and hormones were measured at 0, 15, 30 min and thereafter at 30-min intervals up to 5 h. Results: Glucose, albumin and urea remained constant, peak AA concentrations were achieved at 30 min for methionine (Met), at 60 min for all other AA. The insulin peak (533% compared to basal level, p < 0.01) at 30 min was earlier than the peaks of all AA except for Met. Ghrelin showed a continuous rise towards the end of the experiment leading to a 3-fold increase in initial concentrations in the study group (p < 0.001), significantly higher than in the control group (p < 0.05). In contrast, both groups exhibited almost constant leptin concentrations. Conclusion: Our data indicate that an oral low-dose AA bolus not only causes considerable hyperaminoacidemia and hyperinsulinemia but is also accompanied by an increased ghrelin secretion in fasted humans. This may be a specific effect or may be due to the fact that a single bolus of AA is not a sufficient stimulus to induce satiety. Leptin, however, is not a key mediator in this setting.

Keywords:
Amino acids, Ghrelin, Insulin, Leptin
This content is only available via PDF.
© 2003 S. Karger AG, Basel
2003
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.