Effects of Hysteroscopic and Uterine Body Insemination on the Presence of Selected Immune Cells in the Equine Endometrium.

The research investigates how different methods of horse insemination, specifically standard uterine body and hysteroscopic insemination, impact endometrial health by assessing changes in certain immune cells within the horses’ uterus.

Study Design and Groups

• The study involved 33 mares who were divided into five groups: control (not inseminated), sham AI (artificially stimulated but not inseminated in the uterus), sham HysAI (artificially stimulated but not hysteroscopically inseminated), standard AI (standard uterine body insemination with sperm), and HysAI (hysteroscopic insemination with sperm).
• This categorization was done to observe and compare the possible changes in endometrial health following these different procedures.

Data Collection

• The researchers used several techniques to collect data: uterine swabbing to identify microorganisms, cytology to monitor polymorphonuclear neutrophils (a type of immune cell), and endometrial biopsy to get tissue samples for histology and immune cell characterization.
• Data was collected at three different times: day 18 after ovulation to set a baseline, and then 8-10 hours and 72 hours after insemination to observe immediate and short-term changes following the procedures.

Findings

• The number of microorganisms in mares that underwent sham insemination increased throughout the experiment, pointing to an increase in contamination due to the procedure.
• Significant changes in the percentages of polymorphonuclear neutrophils (PMNs), macrophages, and T cells were observed over time for both the standard AI and the HysAI groups. There was an increase recorded at the 8-10 hour mark after insemination and a subsequent decrease towards baseline levels at 72 hours.
• Differences were also noted in the percentage of PMNs and macrophages between control and sham groups compared to the standard AI procedure. This indicates that increased immune response is related to the presence of sperm in the uterus, suggesting a likely means of preventing infection post-insemination.

Conclusion

• The study concluded that the cellular immune response of the endometrium depends on sperm deposition in the uterus, demonstrating how the uterus responds to potentially foreign elements.
• There was no difference in this immune response between hysteroscopic and standard uterine body insemination, suggesting that both methods have a similar impact on endometrial health. The key factor affecting endometrial immune response appears to be the presence of sperm, rather than the insemination method.