Effect of exogenous ovarian steroids on the uterine luminal prostaglandins in ovariectomised mares with experimental endometritis.

The research article investigates the effect of external ovarian hormones on the changes of prostaglandins in the uterus of mares under induced uterine inflammation. Researchers found that treatment with certain hormones significantly increased prostaglandin concentrations in response to inflammation.

Background and Study Aim

• This study is dealing with endometritis, an inflammatory condition in the uterus of mares – female horses – and how externally introduced ovarian hormones influence the levels of certain prostaglandins (PGs) which are hormone-like substances that play a key role in inflammation and pain within the uterus.
• The aim of the research is to understand the effect of ovarian steroids, particularly progesterone and oestradiol, on the levels of these PGs, namely prostaglandin F (PGF) and prostaglandin E2 (PGE2), in the uterus during a state of inflammation.

Methodology

• Researchers introduced uterine inflammation to mares that had their ovaries removed. They then treated the mares with progesterone, oestradiol, or a combination of the two.
• They assessed the effect of these treatments by measuring the concentration of PGs in the uterine lavage fluid – a washing solution used to clean the uterus.

Major Findings

• The study found that levels of PGF and PGE2 significantly increased when mares were treated with progesterone or a combination of progesterone and oestradiol.
• This pattern was not seen in mares treated only with oestradiol or in control mares, indicating that the ovarian steroids (i.e., progesterone and oestradiol) did influence the production of PGs in the uterus in response to an inflammatory stimulus.

Additional Study

• To determine if the lavage procedure itself might be influencing PG levels, the researchers carried out the procedure on six mares with intact ovaries.
• They found out that barring instances of luteolysis, uterine levels of PGF returned to pre-lavage levels within 30 minutes, signifying that the lavage procedure was unlikely to have influenced the concentrations of prostaglandins in the fluid.