3H-testosterone was incubated and its conversion to 5α-reduced metabolites measured in dispersed anterior pituitary cells before and after separation into fractions with different cell-type distribution by gradient sedimentation at unit gravity. In pituitary cells from 14-day-old female rats, 5α-dihydrotestosterone (DHT) formation (expressed per 105 cells) was several times higher than in those from 14-day-old male and adult male rats. After unit gravity sedimentation the formation of DHT rose with the proportional number and size of gonadotrophs in the fractions of all animal groups studied. In a highly purified population of large gonadotrophs, prepared from 14-day-old females, DHT formation was 23 times higher than in a highly purified population of large somatotrophs, obtained from adult males. Isopicnic sedimentation in a metrizamide gradient partially separated the highly purified preparation of gonadotrophs from contaminating thyrotrophs. In the latter gradient DHT formation was low in the fraction enriched in thyrotrophs. When homologous gradient fractions from the three animal groups studied were compared, differences in DHT formation were of similar rank order of magnitude as differences in the proportional number of gonadotrophs in these fractions. The fractional distribution pattern was highly characteristic for each animal group. It is concluded that pituitary DHT formation occurs primarily in the gonadotrophs and that changes in overall 5α-reductase activity of the pituitary is based, at least in part, on changes in the distribution profile of number and size of the gonadotrophs.

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.