The distribution of substance P was demonstrated by immunohistochemical methods, and receptor binding with 125I-8-iodinated 8-tyrosine-substance P as an analog was used to describe possible specific binding sites in the hypothalamo-hypophysial system of the rat. The immunohistochemical experiments showed fibers exhibiting substance P-immunoreactivity in the external and internal layer of the median eminence. In the external layer some of the fibers were located in apposition to the portal capillaries. In the posterior pituitary substance P-immunoreactive fibers were identified. These terminals varied in size and were located near the capillaries as well as in the neuropil. The anterior lobe contained a number of substance P-immunoreactive fibers distributed around the pituitary cells. The kinetic analysis on crude membrane fractions from anterior and posterior pituitaries revealed the presence of a specific binding site for substance P in the anterior pituitary. These data indicate that substance P may be released from the median eminence and posterior pituitary to the vascular system and reach specific receptors in the anterior pituitary. However, a direct innervation of the anterior pituitary is possible. The lack of binding sites in the posterior pituitary indicates that fibers in this organ release substance P into the blood stream.

This content is only available via PDF.
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.