Endocrine and ovarian responses to combined estradiol benzoate-sulpiride in seasonally anovulatory mares treated with kisspeptin.

The study aimed to determine the effectiveness of integrating kisspeptin-10 (Kp10) into an estradiol benzoate (EB) and sulpiride treatment to induce early cyclicity in anovulatory mares. The research found that Kp10 treatment was successful in stimulating greater endocrine responses and encouraging a larger number of mares to respond with follicle growth or ovulation within 25 days.

Methodology

• The experiment included eighteen anestrous mares that were divided into groups based on breed, body condition, and age and then randomly assigned for treatments or control.
• All mares received 50 mg EB, and then on the next day, osmotic minipumps containing either Kp10 (50 μg/hour) or saline were supplied to them.
• Another day later, all mares received 3 g sulpiride whereupon blood samples were taken daily for 25 days and transrectal ultrasounds were performed on the mares to observe their ovarian activities.

Findings

• Seven out of the nine mares treated with Kp10 responded to the treatment and showed signs of ovarian activity, while only four out of the nine saline-treated mares responded.
• It was noted that the mares treated with Kp10 showed ovarian response sooner (in around 13.7 days) than the mares treated with saline (around 35.9 days).
• There was an increase in plasma prolactin in all mares due to the sulpiride treatment, however, this increase was more pronounced in the Kp10-treated mares.
• Plasma LH increased in all mares after 5 days of sulpiride treatment, but the increase was significantly higher in Kp10-treated mares. Plasma FSH concentrations showed no notable difference between the groups.

Conclusion

The research concluded that the use of Kp10 could enhance the prolactin and LH responses to the EB-sulpiride treatment, leading to a greater number of mares showing early ovarian activity. Thus, the incorporation of Kp10 into treatment could be beneficial for inducing early cyclicity in anovulatory mares.