Mucus production by endometrium of reproductively healthy mares and mares with delayed uterine clearance.

This study aims to compare various laboratory techniques for analysing endometrial, or uterine, samples from healthy mares and those with delayed uterine clearance, specifically looking at mucociliary apparatus, a key part of the reproductive system. The research found that the tools and processes used in sample collection could impact the observations and thus understanding of mucus production, an important aspect of reproductive health.

Goals of the Study

• The study was designed with two main objectives. First, it aimed to evaluate the effectiveness of different staining and fixation techniques used on endometrial biopsy samples, which are necessary for observing the structure and function of the cells.
• Second, it aimed to understand the mucociliary apparatus – the mucous-producing and hair-like structures (cilia) – within the uterus of both healthy horses and those with a condition known as delayed uterine clearance.

Methodology

• The research team collected endometrial samples from healthy mares and mares with delayed uterine clearance during various stages of the reproductive cycle.
• Each sample was preserved using two types of fixative solution, Bouin’s and formalin, and colored with different stains, including alcian blue at two pH levels, periodic acid Schiff (PAS), and mucicarmine.
• These varying methods were used to highlight different features of the samples for further observation and analysis.

Findings

• The study found that the extracellular mucus blanket – a layer of mucus that coats the uterus – was observed more frequently in samples preserved with Bouin’s fixative than with formalin.
• Alcian blue (pH 2.5) staining was found to be most effective at highlighting luminal epithelial cells and the mucus blanket.
• Ciliated cells, which contain hair-like structures, were most easily observed in biopsy samples preserved with formalin and stained with alcian blue (pH 2.5) or mucicarmine.
• The study also found increased mucus production in fibrotic nests and inflamed samples.
• According to image analysis results, the amount of intracellular mucus increases during oestrus, but the secretions become denser during dioestrus.

Conclusion

• The research concluded that mares with delayed uterine clearance produce significantly more mucus than reproductively healthy mares.
• This difference in mucus production may play a pivotal role in understanding and treating mares with delayed uterine clearance and improving their reproductive health.