Direct effect of prolactin, induced by TRH injection, on ovarian oestradiol secretion in the ewe

in Reproduction
Authors:
A. S. McNeilly
Search for other papers by A. S. McNeilly in
Current site
Google Scholar
PubMed Close
and
D. T. Baird
Search for other papers by D. T. Baird in
Current site
Google Scholar
PubMed Close
DOI:
https://doi.org/10.1530/jrf.0.0690559
Volume/Issue:
Volume 69: Issue 2
Page Range:
559–568
Article Type:
Research Article
Online Publication Date:
Nov 1983
Free access

Sign up for journal news

Summary. The effect of sustained high plasma levels of prolactin, induced by repeated 2-h i.v. injections of thyrotrophin-releasing hormone (TRH; 20 μg), on ovarian oestradiol secretion and plasma levels of LH and FSH was investigated during the preovulatory period in the ewe. Plasma levels of progesterone declined at the same rate after prostaglandin-induced luteal regression in control and TRH-treated ewes. However, TRH treatment resulted in a significant increase in plasma levels of LH and FSH compared to controls from 12 h after luteal regression until 5 to 6 h before the start of the preovulatory surge of LH. In spite of this, and a similar increase in pulse frequency of LH in control and TRH-treated ewes, ovarian oestradiol secretion was significantly suppressed in TRH-treated ewes compared to that in control ewes. The preovulatory surge of LH and FSH, the second FSH peak and subsequent luteal function in terms of plasma levels of progesterone were not significantly different between control and TRH-treated ewes.

These results show that TRH treatment, presumably by maintaining elevated plasma levels of prolactin, results in suppression of oestradiol secretion by a direct effect on the ovary in the ewe.

Reproduction is committed to supporting researchers in demonstrating the impact of their articles published in the journal.

The two types of article metrics we measure are (i) more traditional full-text views and pdf downloads, and (ii) Altmetric data, which shows the wider impact of articles in a range of non-traditional sources, such as social media.

More information is on the Reasons to publish page.

Sept 2018 onwards Past Year Past 30 Days
Full Text Views 307 121 0
PDF Downloads 105 32 0

 

  • Collapse
  • Expand
Print ISSN:
1470-1626
Online ISSN:
1741-7899