Effects of gonadotrophin-releasing hormone and prostaglandin F-2α on corpus luteum function and timing of the subsequent ovulation in the mare

Alan Leslie Johnson, S. E. Becker, M. L. Roma

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Standard bred mares that were cycling normally were treated beginning on Days 9 or 10 of the oestrous cycle with repeated pulses of GnRH (20 μg/h) and/or a single injection of prostaglandin (PG)F-2α (alfaprostol, 3 mg), and were subsequently bled and palpated daily until the next ovulation. GnRH treatment increased serum concentrations of LH and progesterone at 4 days after the start of treatment compared to controls. The combination of PGF-2α + GnRH treatment resulted in an immediate decline in serum progesterone values, and subsequently decreased the interval to next ovulation by 4.5 days compared to controls. Mean serum concentrations of FSH were not different among treatment groups 4 days after the start of treatment, and there was a consistent trend among all treatment groups for decreasing concentrations of FSH within the 6 days before ovulation. We conclude that, under our experimental conditions, pulsatile administration of GnRH provides a short-term luteotrophic stimulus, probably by the elevation in serum LH, but that this stimulus cannot indefinitely prevent the luteolytic effects of exogenously administered PGF-2α. Although GnRH treatment combined with PGF-2α injection hastened the impending ovulation, this regimen was no more effective than PGF-2α treatment alone.

Original languageEnglish (US)
Pages (from-to)545-551
Number of pages7
JournalJournal of reproduction and fertility
Volume83
Issue number2
StatePublished - Jan 1 1988

All Science Journal Classification (ASJC) codes

  • Physiology
  • Embryology
  • Molecular Biology
  • Obstetrics and Gynecology
  • Developmental Biology

Fingerprint

Dive into the research topics of 'Effects of gonadotrophin-releasing hormone and prostaglandin F-2α on corpus luteum function and timing of the subsequent ovulation in the mare'. Together they form a unique fingerprint.

Cite this