Time Course of Hyperosmolar Opening of the Blood-Brain and Blood-CSF Barriers in Spontaneously Hypertensive Rats

Abstract

The time course of blood-brain barrier (BBB) and blood-CSF barrier (BCSFB) responses to hyperosmolar mannitol infusion (HMI; 1.6 M) during chronic hypertension was investigated using ¹⁴C-sucrose as a marker of barrier integrity. ¹⁴C-sucrose entry into CSF of both spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats 2 min after HMI increased ∼7-fold compared to their respective control. The volume of distribution (V_d) of ¹⁴C-sucrose into brain cortex of SHR increased 13-fold 2 min after HMI while that in WKY rats increased only 4-fold. After HMI V_d of ¹⁴C-sucrose into the cortex of WKY, and CSF of both SHR and WKY remained steadily greater than their corresponding control for up to 30 min (p < 0.01), whereas in the cortex of SHR the V_d of ¹⁴C-sucrose reached control values 20 min after HMI (p > 0.05), indicating that after HMI the increase in paracellular diffusion of ¹⁴C-sucrose into SHR cortex was not persistent, in contrast to WKY rats and CSF of both SHR and WKY rats. Electron microscopy of the brain cortex after HMI showed capillary endothelial cell shrinkage and perivascular swellings in the brain cortex, and in the choroid plexus opening of tight junctions were observed. Our results indicate disruption of both the BBB and the BCSFB after HMI in both SHR and WKY rats. The disruption remained persistent up to 25 min after HMI at the BBB of WKY rats and BCSFB in both animal groups, while in SHR the protective function of the BBB returned to control values 20 min after HMI.

Journal

Journal ID (publisher-id): JVR

Journal ID (nlm-ta): J Vasc Res

Journal ID (doi): 10.1159/issn.1018-1172

Title: Journal of Vascular Research

Publisher: S. Karger AG

ISSN (Print): 1018-1172

ISSN (Electronic): 1423-0135

Publication date Subscription-year: 2007

Publication date (Print): February 2007

Publication date (Electronic): 28 December 2006

Volume: 44

Issue: 2

Pages: 99-109

Affiliations

^aDepartment of Physiology, Faculty of Medicine, and ^bDepartment of Biological Sciences, Faculty of Science, Kuwait University, Safat, Kuwait

Article

Publisher ID: 98260 Other ID: J Vasc Res 2007;44:99–109

DOI: 10.1159/000098260

PubMed ID: 17191032

Copyright statement: © 2007 S. Karger AG, Basel

License:

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

Figures: 7, References: 42, Pages: 11

Product

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Categories

Subject: Research Paper