Dissociation between Cardiac Cyclic AMP and Myocardial Contractility Induced by Verapamil, Calcium and Magnesium Ions

Abstract

Isolated, perfused rat hearts were used to study the effects of verapamil, excess calcium ions or excess magnesium ions on changes in heart cyclic AMP and myocardial force of contraction. Verapamil caused a dose-dependent decrease in force of contraction and a nondose-related reduction in cyclic AMP. Perfusion of hearts with medium containing 5 m M calcium produced a significant rise in cyclic AMP, but no change in contractile force. The depressant effects of verapamil on contractility and cyclic AMP were reversed by 5 m M calcium; excess calcium in the perfusion fluid also containing verapamil prevented the myocardial depresant effects of verapamil. Acutely elevating the magnesium concentration in the perfusion medium decreased force of contraction, accentuated the negative inotropic effect of verapamil, but did not decrease cyclic AMP or enhance the verapamil-induced reduction in cyclic AMP.

Journal

Journal ID (publisher-id): CRD

Journal ID (nlm-ta): Cardiology

Journal ID (doi): 10.1159/issn.0008-6312

Title: Cardiology

Publisher: S. Karger AG

ISSN (Print): 0008-6312

ISSN (Electronic): 1421-9751

Publication date Subscription-year: 1979

Publication date (Print): 1979

Publication date (Electronic): 31 October 2008

Volume: 64

Issue: 2

Pages: 75-86

Affiliations

Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, Pa.

Article

Publisher ID: 170581 Other ID: Cardiology 1979;64:75–86

DOI: 10.1159/000170581

PubMed ID: 219956

Copyright statement: © 1979 S. Karger AG, Basel

License:

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: 12

Product

Self URI (application/pdf): https://www.karger.com/Article/Pdf/170581

Self URI (text/html): https://www.karger.com/Article/FullText/170581

Self URI (journal page): https://www.karger.com/SubjectArea/Cardiovascular-System

Categories

Subject: Original Paper