Our current understanding of the pathophysiology of equine endometritis with an emphasis on breeding-induced endometritis.
Abstract: Equine endometritis is characterized by the expression of pro- and anti- inflammatory cytokines and an influx of polymorphonuclear neutrophils (PMNs) into the uterus. Mares resistant to persistent endometritis clear the inflammation within 24-36 h after exposure to microorganisms or semen. These mares have a rapid increase of pro-inflammatory cytokines and an upregulation of inflammatory modulating cytokines within 6h after exposure to inflammatory challenge. In conjunction with effective uterine contractions, these events are believed to be responsible for the transient nature of the inflammation. In contrast, mares that are susceptible to persistent endometritis fail to clear the inflammation in a timely fashion. They have an imbalanced endometrial mRNA expression of pro- and anti-inflammatory cytokines, and have also been shown to suffer from an accumulation of intraluminal nitric oxide, which may be related to impaired myoelectrical activity and delayed uterine clearance. As a consequence, these mares establish a chronic inflammation, which interferes with the establishment of pregnancy. Recent studies on endometrial cytokine expression in resistant and susceptible mares have revealed information that suggest an underlying immunologic basis for susceptibility to persistent endometritis. However, the inflammatory pathways have yet not been fully studied, and a relationship between cytokine expression, nitric oxide, and myometrial contractions has not been established. In addition, seminal plasma has been shown to modulate breeding induced inflammation, but the molecular basis of the modulation is not understood. A holistic approach appears to be needed to better understand the characteristics of inflammatory pathways and ultimately the pathophysiology of the disease.
Copyright © 2016. Published by Elsevier Urban & Partner Sp. z o.o.
Publication Date: 2016-01-29 PubMed ID: 26952748DOI: 10.1016/j.repbio.2016.01.003Google Scholar: Lookup
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Summary
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The research article is exploring the pathophysiology of equine endometritis, focusing specifically on the differing responses in horses resistant to persistent endometritis compared to those susceptible to it. The article also discusses how semen can modulate this inflammation.
Understanding of Equine Endometritis
- The study focuses on equine endometritis, an inflammation of the uterus in horses which is characterized by the expression of pro- and anti-inflammatory cytokines along with an influx of polymorphonuclear neutrophils (PMNs) into the uterus.
- This inflammation can be triggered by exposure to both microorganisms and semen, which is particularly relevant during the breeding process when inflammation is induced.
Response to Inflammation
- Equine responses to endometritis are categorized into two types. Horses resistant to persistent endometritis can clear inflammation within 24-36 hours after exposure to triggering substances. This ability is credited to a swift increase in pro-inflammatory cytokines and an upregulation of those that modulate inflammation within a 6-hour window post-exposure.
- Effective uterine contractions contribute to this quick clearance of inflammation, causing the inflammation to exhibit a transient nature in these resistant horses.
Persistent Endometritis
- Contrastingly, horses susceptible to persistent endometritis cannot clear inflammation in a timely manner. These horses demonstrate an imbalance in the endometrial mRNA expression of pro- and anti-inflammatory cytokines.
- These susceptible horses may also experience an accumulation of intraluminal nitric oxide, potentially related to impaired myoelectrical activity, leading to delayed uterine clearance.
- The chronic inflammation that results from this persistence interferes with the successful establishment of pregnancy in these horses.
Immunological Basis and Further Research Needed
- Recent studies have suggested a potential immunological basis for the susceptibility to persistent endometritis. This focuses on the endometrial cytokines expressed in resistant and susceptible horses.
- However, these inflammatory pathways need further study for a fuller understanding and, as of now, a clear relationship has not been established between cytokine expression, nitric oxide, and uterine contractions.
- Additionally, it has been observed that seminal plasma can influence breeding-induced inflammation but the molecular basis of this effect is not yet known.
- The research suggests that a more holistic approach may be necessary to better comprehend the intricacies of the inflammatory pathways and the overall pathophysiology of equine endometritis.
Cite This Article
APA
Troedsson MH, Woodward EM.
(2016).
Our current understanding of the pathophysiology of equine endometritis with an emphasis on breeding-induced endometritis.
Reprod Biol, 16(1), 8-12.
https://doi.org/10.1016/j.repbio.2016.01.003 Publication
Researcher Affiliations
- Maxwell H. Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546-009, USA. Electronic address: M.Troedsson@uky.edu.
- Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, 382 West Street Road, Kennett Square, PA 19348, USA.
MeSH Terms
- Animals
- Copulation
- Endometritis / pathology
- Endometritis / veterinary
- Female
- Horse Diseases / physiopathology
- Horses
- Infertility / veterinary
- Male
Citations
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