+1 Recommend
1 collections
      • Record: found
      • Abstract: found
      • Article: found

      Unique Vasocontraction of Okadaic Acid Isolated from Black Sponge, Independent of Extracellular Ca 2+

      Journal of Vascular Research

      S. Karger AG

      Okadaic acid, Human umbilical artery, Rabbit aorta, Ca2+-free medium

      Read this article at

          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.


          Okadaic acid (OA) isolated from black sponge ( Halichondria) caused tonic contractions of human umbilical arteries and rabbit aorta both in the presence and absence of Ca<sup>2+</sup>. This tonic contraction was not affected by Ca<sup>2+</sup> chelator, Ca<sup>2+</sup> entry blockers and La<sup>3+</sup>. In addition, the antagonists of alpha-adrenoceptors, histamine, serotonin and ACh receptors had no effect on the OA-induced contraction. High K, ouabain and indomethacin failed to inhibit the response to OA. However, the combination of anaerobic conditions and absence of glucose abolished the response to OA. OA had no effect on the myosin B ATPase and saponin-treated skinned fibers of rabbit aorta. The contractile action of OA may not also be related to calmodulin-related PDE and mitochondrial respiration. In conclusion, although the precise mode of action is not evident at the present time, OA, in its unique pharmacological action – that of producing sustained contraction independent of extracellular Ca<sup>2+</sup> -may alter the handling of Ca<sup>2+</sup> to intracellular store sites.

          Related collections

          Author and article information

          J Vasc Res
          Journal of Vascular Research
          S. Karger AG
          23 September 2008
          : 24
          : 3
          : 104-107
          Department of Pharmacology, School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
          158679 Blood Vessels 1987;24:104–107
          © 1987 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: 4
          Neurohumoral Control of Blood Vessel Tone


          Comment on this article