Modulation of oviductal transport in mares by local application of prostaglandin E2.
Abstract: Equine embryos enter the uterus 144-156 h after ovulation, before which time the passage of embryos through the oviduct is halted in the region of the ampullary-isthmic junction. It is thought that further onward movement of embryos to the uterus is facilitated by secretion of prostaglandin E2 (PGE2) by the embryos, which relaxes the smooth muscle of the isthmus. In the present study, the effect of a single local application of PGE2 on oviductal transport was examined in 22 Thoroughbred and Pony mares that were inseminated on alternate days during oestrus. On day 4 after ovulation, the ipsilateral ovary, oviduct and tip of the uterine horn were visualized by flank laparoscopy, and either a commercial preparation of PGE2 suspended in a triacetin-based gel or a control gel containing no PGE2 was dripped along the external surface of the oviduct. On day 5, the uterus of each mare was flushed three times with phosphate-buffered saline containing 1% (v/v) fetal bovine serum and, if no embryo was recovered, the flushing procedure was repeated on day 7 or 8. Overall, the embryo recovery rate was similar in PGE2-treated and control mares (65 and 63%, respectively). However, the recovery rate of embryos on day 5 was significantly higher for PGE2-treated mares than for control mares (60 versus 0%; P < 0.01), indicating an increased rate of embryo transport in PGE2-treated mares. Furthermore, unfertilized oocytes were recovered from nine of the PGE2-treated mares on day 5 but from none of the control mares. All of the embryos recovered on day 5 were compacted morulae, whereas all of those recovered on days 7 or 8 were expanding blastocysts. The results of the present study support the role of embryonic PGE2 in oviductal transport in mares. The results also demonstrate that a single local application of PGE2 is a simple and practical method for speeding the passage of embryos through the oviduct for nonsurgical recovery of morulae from the uterus.
Publication Date: 2000-01-01 PubMed ID: 20681173
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- Clinical Trial
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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This research examines the effect of applying prostaglandin E2 locally to enhance the transport of embryos in the oviducts of mares. The study found that single local application of prostaglandin E2 facilitates the faster transport of embryos.
Objective of the Study
- The research primarily aimed to study the influence of a single local application of prostaglandin E2 (PGE2) on the transport of embryos within the oviduct of mares. PGE2 is believed to relax the smooth muscle of the isthmus, a section of the female reproductive tract, to help progress the embryos to the uterus.
Methodology
- A total of 22 Thoroughbred and Pony mares were inseminated during oestrus (the time in the reproductive cycle when horses are sexually receptive) on alternate days.
- On day 4 post-ovulation, part of the female reproductive tract was examined using flank laparoscopy. One group of mares received an application of a commercial preparation of PGE2 in a gel, while the control group splashed with a gel without PGE2.
- The uterus of each mare was flushed on day 5 with phosphate-buffered saline and 1% fetal bovine serum. If no embryo was recovered on day 5, the process was repeated on days 7 or 8.
Findings
- The rate of embryo recovery was comparable between the PGE2-treated group and the control group. However, on day 5, the embryo recovery was significantly higher from the PGE2-treated mares compared to the control group, indicating that PGE2 application increased the rate of embryo transport.
- Additionally, unfertilized oocytes were found only in the PGE2-treated mares on day 5, not in the control group.
- Embryos recovered on day 5 were compacted morulae (an early-stage embryo), while those recovered on days 7 or 8 were expanding blastocysts (a later stage of embryonic development).
Implications
- The research supported the belief that embryonic PGE2 facilitates the transport of embryos in the oviducts of mares.
- The findings suggest that a single local application of PGE2 could be a practical method to accelerate the passage of embryos through the oviduct, making non-surgical recovery of morulae from the uterus possible.
Cite This Article
APA
Robinson SJ, Neal H, Allen WR.
(2000).
Modulation of oviductal transport in mares by local application of prostaglandin E2.
J Reprod Fertil Suppl(56), 587-592.
Publication
Researcher Affiliations
- Department of Clinical Veterinary Medicine, Equine Fertility Unit, University of Cambridge, Mertoun Paddocks, Woodditton Road, Newmarket CB8 9BH, UK.
MeSH Terms
- Animals
- Dinoprostone / pharmacology
- Drug Administration Routes
- Embryo, Mammalian / physiology
- Female
- Horses / physiology
- Oviducts / drug effects
- Pregnancy
Citations
This article has been cited 4 times.- Lawson EF, Grupen CG, Baker MA, Aitken RJ, Swegen A, Pollard CL, Gibb Z. Conception and early pregnancy in the mare: lipidomics the unexplored frontier. Reprod Fertil 2022 Jan 1;3(1):R1-R18.
- Bazer FW, Song G, Thatcher WW. Roles of conceptus secretory proteins in establishment and maintenance of pregnancy in ruminants. Asian-Australas J Anim Sci 2012 Jan;25(1):1-16.
- Hendrickson DA. A review of equine laparoscopy. ISRN Vet Sci 2012;2012:492650.
- Scoggin KE, Adlan F, Fedorka CE, Rakha SI, Stout TAE, Troedsson MHT, Ali HE. Gestation-Stage Related Changes in the IGF System Components in the Equine Placenta. Biomolecules 2025 Aug 6;15(8).
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