We have previously characterized two normotensive strains of rats which differ markedly in their susceptibility to spontaneous rupture of the internal elastic lamina (IEL), the Brown Norway (BN) being very susceptible and the Long Evans (LE) being resistant. Here we quantified biochemically the elastin and collagen content of aortae from adult male BN and LE rats aged 12,18 and 22 weeks and showed that the elastin content was lower and the collagen content higher in the BN strain than in the LE strain, resulting in a markedly lower elastin/collagen ratio in the former strain. These modifications were present both in the thoracic aorta, which is devoid of IEL ruptures, and in the abdominal segment where ruptures frequently occur in the BN rat, suggesting that they could represent a predisposing factor in the presence of other local factors. Quantifications of relevant mRNAs in aortae of younger male BN and LE rats by Northern blot showed that there are lower tropoelastin transcript levels in the BN rat at 6 weeks in both thoracic and abdominal segments than in the age-matched LE rat. In contrast there was no consistent interstrain difference in α1 type I collagen transcripts and α1 type III collagen transcripts were higher in the BN aorta only at 6 weeks in the abdominal segment. We conclude that the BN rat presents an aortic elastin deficit which appears to be in part explained by a decreased elastin synthesis in young, growing rats and may be genetically determined. However, a direct relation of this elastin deficit with susceptibility to rupture of the IEL cannot be concluded from this study.

Keywords:
Aorta, Elastin, Collagen, orthern blot
This content is only available via PDF.
© 1997 S. Karger AG, Basel
1997
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.