[Endometrial cups in horses].

The research article focuses on endometrial cups in horses, special outgrowths in the uterus of pregnant mares, their formation, function, properties, and the hormonal substances they produce.

Introduction and Basics of Endometrial Cups

• Endometrial cups are unique formations that appear in the uterine wall of pregnant horses, specifically in the gestation period between 38 days and 150 days.
• They vary in shape, from oval to irregular, typically having distinct raised edges and an appearance similar to ulcers.
• The maximum measurements of these cups are about 5 X 2.5 X 2.5 cm.
• Under a microscopic lens, these structures consist of large epithelioid decidual-like cells that have large nucleoli.

Endometrial Cups and Hormone Production

• These endometrial cups are significant because they produce a hormone known as Pregnant Mare Endometrium Gonadotrophin (PMEG).
• The research suggests that PMEG may be a precursor of the hormone Pregnant Mare Serum Gonadotrophin (PMSG).
• PMSG can be detected in the bloodstream of mares, pointing towards substantial involvement in the equine gestation process.
• However, the exact function of PMSG remains unclear, but the research paper poses potential possibilities.

Regression of Endometrial Cups

• Approximately after 70 days of gestation, the regression or reduction of the endometrial cups begins.
• The regression process is driven by the immune system, more specifically, the cellular branch.
• The humoral branch of the immunity system, responsible for the production of antibodies, also plays a protective role in the regression process, potentially by generating ‘blocking’ antibodies.
• This finding points to the dynamic interaction between the immune system, endometrial cups, and the overall gestation process in horses.