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

      Thyroid Hormone Regulation of Neurons Staining for a Pro-TRH-Derived Cryptic Peptide Sequence in the Rat Hypothalamic Paraventricular Nucleus

      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 influence of thyroid hormones on neurons staining for a pro-TRH-derived cryptic peptide sequence in the rat hypothalamic paraventricular nucleus was assessed by using quantitative immunocytochemistry. The antiserum used for immuno-cytochemical studies recognized a cryptic fragment of pro-TRH located in the Phe 178-Ser 186 region of the precursor. Hypothyroid female rats obtained following 1 month administration of 6-n-propyl-2-thiouracil (PTU) as well as euthyroid animals were treated with a low (3 µg/kg/day) or high (67 µg/kg/day) dose of L-thyroxine (T<sub>4</sub>) for 4–10 days before sacrifice. All the animals received an intraventricular injection of colchicine 2 days prior to perfusion with 4% paraformaldehyde. PTU treatment induced an increase (45% over control) in the number of immunostained neurons. The administration of a low dose of T<sub>4</sub> to hypothyroid animals slightly increased the number of staining for a pro-TRH-derived cryptic sequence neurons, while being uneffective in euthyroid rats. In hypothyroid animals, a 4-day treatment with the high dose of T<Sub>4</sub> did not produce any changes whereas the 7-day treatment reduced the number of positive cells to 42% of control. In euthyroid rats treated with the high dose of T<sub>4</sub> for 4 and 7 days, the number of stained neurons was reduced to 60 and 37% of control, respectively. These results indicate that thyroid hormones can modify the amounts of staining for a pro-TRH-derived cryptic sequence in hypothalamic paraventricular neurons. They also suggest that thyroid hormones can regulate TSH secretion, not only at the pituitary level, but also by modifying the activity of neurons staining for a pro-TRH-derived cryptic sequence in the hypothalamic paraventricular nucleus.

          Related collections

          Author and article information

          S. Karger AG
          02 April 2008
          : 50
          : 2
          : 217-221
          aMRC Group in Molecular Endocrinology, Laval University Medical Center, Sainte-Foy, Canada; bLaboratoire d’Endocrinologie Moléculaire, UA CNRS 650, Unité Alliée à ΓINSERM, Université de Rouen, France
          125225 Neuroendocrinology 1989;50:217–221
          © 1989 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: 5
          Original Paper


          Comment on this article