Influence of two ovulation-inducing agents on the pituitary response and follicle blood flow in mares.

This research paper examines the effects of two treatments, deslorelin and hCG, on ovulation processes in mares. Thorough analysis was conducted to study their impact on the LH (Luteinizing Hormone) surge, an important event leading to ovulation, and the blood flow in the follicle, a critical factor affecting ovulation and overall reproductive health.

Research Methodology—-

• Thirty mares participating in this study were divided into three groups and treated with deslorelin, hCG, or NaCl 0.9% saline.
• Researchers conducted a power-flow Doppler examination and collected blood samples hourly during the initial 12 hours post-treatment, and every six hours from the 12th to the 30th hour.
• The study also followed an hourly evaluation in the final six hours leading up to ovulation.

Key Findings—-

• In the group treated with deslorelin, there was a significant rise in plasma LH concentration during the first 6 hours after the treatment, which remained high until 1 hour before ovulation.
• In contrast, the hCG-treated group witnessed an increase in LH concentrations pre-ovulation, specifically at 24 hours after treatment, while the saline group showed no significant change.
• There were no major variations across the treatments in the percentage of the follicle wall showing Doppler signals, indicating that the follicle blood flow did not alter significantly in the entire experiment across all treatments.
• A weak correlation was discovered between the vascularity of the preovulatory follicle and the concentration of plasma LH in all groups.

Conclusion—-

• This research presents the first description of the immediate and sustained pituitary response to ovulation-inducing treatment with injectable deslorelin.
• The study also illustrates that increases in follicle blood flow do not necessarily precede spontaneous or induced ovulations specific to mares. This refutes previously held beliefs about the role of follicle vascularity in ovulation for large animals.