Apical regions of the left ventricular myocardium of female C57BL/6J mice, aged between 6 and 27 months, that had been subjected to endurance running for 2, 10 or 15 months, were examined by light and electron microscopy. Focal degenerative changes were found in myocytes of these experimental mice, including loss of myofibrils, erosion of myo-cytes and changes in nuclei, lipofuscin content and mitochondria. The interstitial connective tissue showed an increase in collagen in aged myocardia. Endurance-trained runners frequently showed signs of platelet aggregation or microthrombi in small capillaries associated with myocytes. These were most common in endurance-trained middle-aged and very elderly mice, but were not found in sedentary age-matched controls. Our experiments indicate that running stress may be damaging to cardiac tissue in aged animals. Our findings may be of significance in helping the understanding of the development and the etiology of stress-induced cardiovascular damage in the elderly.

Keywords:
Ultrastructure, Myocardium, Exercise
© 1987 S. Karger AG, Basel
1987
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.