Uterine Inflammatory Response After Prostaglandin E1 (Misoprostol) Infusion Prebreeding or Immediately After Embryo Flushing in Commercial Donor Mares.

The research involves a study on horses to understand the effects of a drug, misoprostol, on inflammation in the uterus. The study shows that the use of the drug does not cause any significant increase in inflammation either when administered before breeding or after flushing out embryos from the uterus.

Research Overview

• This study was focused on understanding the effects of misoprostol, a synthetic prostaglandin E1, on inflammation in the uterus of female horses (mares). Misoprostol has recently been used to treat suspected uterine tube blockages in mares. However, there have been concerns about whether the drug might induce more severe inflammation in the uterus.
• The research involved two experiments: one where the misoprostol was administered prebreeding and the other right after embryo flushing (the process of removing embryos from the uterus for further study or manipulation).
• Eleven privately owned mares that typically serve as embryo donors were used in the study. The mares were randomly assigned to receive the misoprostol or a sham treatment (lactate Ringer’s solution). The sham injections were used to act as a control for comparison.

Method and Observations

• Both the misoprostol and sham injections were administered bilaterally and deep into the uterine horns of the mares.
• The mares were monitored for various signs of inflammation (uterine edema, fluid accumulation, and the number of polymorphonuclear leukocytes, or PMN) and were assessed every day for up to 72 hours after the infusion.
• Additionally, the researchers performed a uterine lavage (a washing out of an organ or cavity) the day after the infusions. Embryos were flushed out from the uterus 8 to 9 days after ovulation which was monitored and confirmed at 24-hour intervals by a GnRH agonist.
• The study revealed that the infusions of both the misoprostol and sham treatments did result in increased PMN for up to 48 hours post-infusion, but other signs of uterine inflammation (edema or fluid accumulation) were not significantly affected.
• Moreover, the rates of embryo recovery were found to be similar between the misoprostol and sham treatment cycles, suggesting that the misoprostol did not have a detrimental impact on fertility.

Conclusion

• Based on the results of this study, the researchers concluded that misoprostol did not induce exacerbated uterine inflammation in the mares when infused either prebreeding or immediately after embryo flushing. Despite the increase in the PMN count, there were no other evidences of inflammation or systemic adverse reactions to the drug observed. This could make it a potentially safe treatment option for conditions related to uterine tube blockages in mares.