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

      Differences in Function and Structure of the Capillary Endothelium in the Supraoptic Nucleus and Pituitary Neural Lobe of Rats

      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.


          The physiology and structure of capillary endothelial cells in the hypothalamic ventromedial and supraoptic nuclei and pituitary neural lobe were evaluated with quantitative methods and compared. The capillary endothelial cells in the ventromedial nucleus were used as an index of blood-brain barrier endothelium in cerebral gray matter; this endothelium has relatively low surface area and low permeability to tracer solutes. The permeability × surface area product of endothelial cells for a neutral amino acid, <sup>14</sup>C-alpha-aminoisobutyric acid (AIB), in the ventromedial nucleus was similar to the value for supraoptic nucleus and was several hundred times smaller than in the neural lobe. The supraoptic nuclei and neural lobe had exceptionally large capillary surface areas, but dissimilar rates of blood flow and transendothelial influx of AIB. Differences in permeability of the endothelial cells between these two structures correlated closely with their marked dissimilarities in morphology. The neural lobe endothelium had numerous fenestrations (five per capillary cross-section) and vesicular profiles (twice as many as supraoptic nucleus), two features commonly associated with high capillary permeability. The capillary endothelium of the supraoptic nucleus was that of a typical blood-brain barrier structure having intercellular junctions that appeared tight, no fenestrations, and few cytoplasmic pits and vesicles. The unusually large capillary surface area of the supraoptic nucleus and low rate of solute flux across its endothelial cells make this nucleus a unique structure in which rapid changes in tissue volume may occur in response to small perturbations in plasma osmolality. The findings implicate the supraoptic nucleus as an osmotically sensitive detector or ‘osmometer’ in neuroendocrine regulation of body fluid homeostasis.

          Related collections

          Author and article information

          S. Karger AG
          01 April 2008
          : 44
          : 4
          : 401-407
          Department of Neurological Surgery, Health Sciences Center, State University of New York, Stony Brook, N.Y., USA
          124678 Neuroendocrinology 1986;44:401–407
          © 1986 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: 7
          Original Paper


          Comment on this article