help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Tonkowicz, P. A.
Right arrow Articles by Voogt, J. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tonkowicz, P. A.
Right arrow Articles by Voogt, J. L.

Endocrinology, Vol 113, 1314-1318, Copyright © 1983 by Endocrine Society

ARTICLES

Termination of prolactin surges with development of placental lactogen secretion in the pregnant rat

PA Tonkowicz and JL Voogt

It has been hypothesized that it is rat placental lactogen (rPL) which causes PRL surges to terminate at mid-pregnancy. Using a hormonally induced model of delayed implantation, the temporal relationship between the secretion of rPL and the nocturnal PRL surges was followed. Implantation was prevented by removing the ovaries, the source of estrogen, on day 3 of pregnancy. Blastocysts were maintained free- floating in the uterine lumen by sc injection of 4 mg progesterone in oil daily for 0, 5, 7, or 9 days. Implantation was induced and the subsequent pregnancy was maintained with 1 microgram estrone plus 4 mg progesterone daily. Nocturnal PRL surges (0500 h) were followed for 10 days after the first estrone injection. Control animals last exhibited PRL surges on day 10. Animals with 5, 7, or 9 days of implantation delay had their last PRL surge on days 15, 17, and 18, respectively. Levels of rPL in control animals, as measured by Nb2 lymphoma cell bioassay, were low on day 6, slightly higher on day 10, and significantly elevated on day 12. Delaying implantation delayed the increase in rPL secretion in the experimental groups. This proportionately prolonged the number of days the PRL surges were present. These data suggest that the termination of the nocturnal PRL surges requires the secretion of rPL by the developing conceptus.


This article has been cited by other articles:


Home page
 EndocrinologyHome page
F. J. Steyn, G. M. Anderson, and D. R. Grattan
Hormonal Regulation of Suppressors of Cytokine Signaling (SOCS) Messenger Ribonucleic Acid in the Arcuate Nucleus during Late Pregnancy
Endocrinology, June 1, 2008; 149(6): 3206 - 3214.
[Abstract] [Full Text] [PDF]

Home page
 EndocrinologyHome page
G. M. Anderson, P. Beijer, A. S. Bang, M. A. Fenwick, S. J. Bunn, and D. R. Grattan
Suppression of Prolactin-Induced Signal Transducer and Activator of Transcription 5b Signaling and Induction of Suppressors of Cytokine Signaling Messenger Ribonucleic Acid in the Hypothalamic Arcuate Nucleus of the Rat during Late Pregnancy and Lactation
Endocrinology, October 1, 2006; 147(10): 4996 - 5005.
[Abstract] [Full Text] [PDF]

Home page
 EndocrinologyHome page
Z. B. Andrews, I. C. Kokay, and D. R. Grattan
Dissociation of Prolactin Secretion from Tuberoinfundibular Dopamine Activity in Late Pregnant Rats
Endocrinology, June 1, 2001; 142(6): 2719 - 2724.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
M. E. Freeman, B. Kanyicska, A. Lerant, and G. Nagy
Prolactin: Structure, Function, and Regulation of Secretion
Physiol Rev, October 1, 2000; 80(4): 1523 - 1631.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1983 by The Endocrine Society