PGFM response to exogenous oxytocin and determination of the half-life of oxytocin in nonpregnant mares.

The research investigates the half-life of the hormone oxytocin in mares and studies the response of prostaglandin, measured through its metabolite PGFM, following administration of oxytocin. It was found that the half-life of oxytocin remained consistent, regardless of dosage or treatment day, at 6.8 minutes. A noticeable increase in PGFM was observed within 6 minutes of injecting oxytocin, with peak levels seen within 10 minutes. PGFM response was higher when oxytocin was administered on the day of ovulation compared to two days after.

Objective of the Research

• The main objective of the study was to determine the half-life of oxytocin in mares that are reproductively normal and to study the response of the hormone Prostaglandin, which was measured through its metabolite known as PGFM, after administering oxytocin to the mares.

Methodology

• The mares used in the study were given different doses of oxytocin. Two doses were used: 10 and 25 IU. They were administered intravenously on two different days. One set of mares received the treatment on the day of ovulation and the other two days after ovulation.
• After the oxytocin was given, regular blood samples were collected from the mares’ jugular veins. These samples were then analyzed for the presence and concentration of both oxytocin and the metabolite PGFM.

Results

• The half-life of oxytocin was found to be 6.8 minutes. This didn’t change with either the dosage of oxytocin or the timing of treatment, suggesting that the body’s metabolism of oxytocin remained consistent across different conditions.
• A significant rise in the PGFM was witnessed within the first 6 minutes of administering the oxytocin. This increased even further, peaking within 10 minutes. This showed a direct and relatively quick response of Prostaglandin with the introduction of oxytocin.
• There was a noticeable change in the way PGFM responded based on the timing of the oxytocin administration. The PGFM response was higher when oxytocin was administered on the day of ovulation compared to two days after it.