Blog
About

8
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      Phorbol Ester-Induced Contractions of Swine Carotid Artery Are Supported by Slowly Cycling Crossbridges Which Are Not Dependent on Calcium or Myosin Light Chain Phosphorylation

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          This study determined if phorbol ester-induced contraction of vascular smooth muscle requires calcium-dependent myosin light chain (MLC) phosphorylation and, if not, whether the mechanical characteristics of the contraction in terms of stiffness and crossbridge cycling are similar to those during a calcium- and MLC phosphorylation-dependent contraction. Carotid arterial strips were exposed to 1.0 µ M phorbol 12, 13-dibutyrate (PDBu) in the presence of normal physiological salt solution (PSS) or after calcium depletion in calcium-free PSS and compared with contraction elicited by calcium-containing 110 m M KCl-PSS. PDBu induced maximal stress in both the presence and absence of calcium. While there was a temporal correlation between MLC phosphorylation and shortening velocity during KC1 depolarization, shortening velocity was dissociated from MLC phosphorylation during PDBu stimulation. The stress-stiffness relationship was not different during KC1 and PDBu stimulation, suggesting similar crossbridge interactions even though MLC phosphorylation levels were significantly different. These results demonstrate that PDBu-induced contraction of the swine carotid artery is not dependent on calcium or MLC phosphorylation. We suggest the possibility that activation of a calcium-independent PKC isoform may result in the expression of an inherent level of actin-activated myosin ATPase activity resulting in the slow development of stress.

          Related collections

          Author and article information

          Journal
          JVR
          J Vasc Res
          10.1159/issn.1018-1172
          Journal of Vascular Research
          S. Karger AG
          1018-1172
          1423-0135
          1993
          1993
          23 September 2008
          : 30
          : 6
          : 315-322
          Affiliations
          aBockus Research Institute, and bDepartment of Surgery, Graduate Hospital, Philadelphia, Pa., and cWeis Center for Research, Geisinger Clinic, Danville, Pa., USA
          Article
          159012 J Vasc Res 1993;30:315–322
          10.1159/000159012
          8241364
          © 1993 S. Karger AG, Basel

          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: 8
          Categories
          Research Paper

          Comments

          Comment on this article