Corticotropin-releasing factor (CRF) has been characterized on the basis of its intrinsic activity to release corticotropin from cultured rat anterior pituitary cells. Injected in intact rats, CRF increases adrenocorticotropic hormone (ACTH) release. Endogenous CRF-like immunoreactivity was detected in the cytoplasm and nucleus of corticotrophs. Using an antirat CRF serum, a similar location of CRF-like immunoreactivity was observed in lactotrophs: cytoplasmic matrix, secretory granules, nucleus and, to a lesser degree, the plasma membrane level were stained. One injection of CRF increased the plasma ACTH concentration 4-fold after 15 min, while plasma prolactin (PRL) increased 2.7-fold 5 min after injection. In vitro, incubation of female pituitary cells with rat CRF (10–10–10–8M) had no significant effect on PRL secretion. In contrast, after 4 days of in vitro pretreatment with 17β-estradiol (10–9M), rat CRF stimulated PRL secretion by 42%. In situ hybridization of whole pituitary slices showed that rat CRF injection significantly increased the labeling of corticotrophs using an ACTH-cDNA probe, but had no significant effect on the labeling of lactotrophs using a PRL riboprobe. These results indicate that CRF is a factor which can modulate PRL release but not the synthesis of PRL.

Keywords:
Corticotropin-releasing hormone, Prolactin, Adrenocorticotropic hormone, Corticotrophs, Lactotrophs, in situ hybridization
This content is only available via PDF.
© 1989 S. Karger AG, Basel
1989
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.