Steroids affect gene expression, ciliary activity, glucose uptake, progesterone receptor expression and immunoreactive steroidogenic protein expression in equine oviduct explants in vitro.

The research study investigates how steroids, specifically progesterone and 17β-oestradiol, affect the morphology, gene expression, and functionality of the equine oviduct. The study reveals that changing levels of these steroids can significantly impact the oviduct and potentially early embryonic development in horses.

Research Methodology

• In this study, an in-vitro model system of the equine oviduct was used. The oviduct explant culture was exposed to physiological concentrations of steroids namely, progesterone and 17β-oestradiol.
• The researchers created four conditions to compare: preovulatory explants without supplements, preovulatory explants complimented with postovulatory hormone concentrations, postovulatory explants with no supplements, and postovulatory explants with preovulatory hormone concentrations.

Investigation Parameters

• Several parameters were studied with a view to understand the impacts of steroids on oviduct explants, including ciliary activity, glucose and lactate production, ultrastructure, mRNA expression of embryotrophic genes, oviduct explant’s ability to produce steroids, and progesterone receptor expression.

Key Findings

• The research reveals that the equine oviduct is not just an organ transporting the egg, but it has steroidogenic abilities, meaning it has potential to produce steroids.
• The study also demonstrates that the equine oviduct is very responsive to local changes in progesterone and 17β-oestradiol levels. These changes can impact the oviduct at the level of morphology, functionality, and gene expression. Essentially, any changing levels of these steroids can have significant impact on the overall health and function of the oviduct.

Implications of the Research

• The findings of this research provide insights on the importance of endocrine and paracrine signalling during early embryonic development in horses. This is crucial as it will provide valuable understanding of how the internal environment can impact the surviving and thriving of the embryo in its early stages.
• This research forms a foundation for further studies into understanding the complex dynamics between hormones and the reproductive health of equines, potentially contributing to innovative improvements in horse breeding strategies and protocols.