Metabolomics analysis of the effect of GnRH on the pregnancy rate of ewes with estrus synchronization scheme based on progesterone

ABSTRACT:

Introduction: Gonadotropin-releasing hormone (GnRH) is widely used in the timed artificial insemination program of sheep industry, but there is still controversy about the effect of GnRH on pregnancy rate in the process of artificial insemination. Our research shows that the use of GnRH reduces the pregnancy rate. This study aims to analyze the metabolite changes caused by GnRH in Huyang ewes before the implantation period through metabolomics technology, and reveal the mechanism behind the decreased pregnancy rate.

Methods: All ewes had a polyurethane sponge containing 45 mg of flurogestone acetate placed in their vagina for 12 days, and were intramuscularly treated with 330 units of equine chorionic gonadotropin (eCG) immediately after sponge removal. The experimental group (n = 69) received an intramuscular treatment of 17 μg GnRH agonist triptorelin (Day 0) 48 h after sponge removal, while the control group (n = 41) was treated with 1 mL of sterile saline. All ewes underwent a single vaginal insemination 58 h after the withdrawal of progesterone sponges. The difference in pregnancy rates between the two groups was then measured. Metabolomic analysis was performed on plasma samples collected on Day 7.

Results: Compared with the control group, GnRH treatment significantly reduced the pregnancy rate in the experimental group (72.2% vs 82.9%, P < 0.05). Metabolomic analysis revealed that GnRH treatment influenced metabolites involved in collagen synthesis and metabolites linked to prostaglandin synthesis in the endometrial tissue, which includes a marked decrease in hydroxyproline metabolite content and a substantial increase in corticosterone and prostaglandin D2 metabolite levels.

Conclusion: In summary, GnRH agonist Triptorelin injected 48 h after the withdrawal of progesterone sponges can reduce the pregnancy rate of Huyang ewe after artificial insemination and affect the metabolite levels related to endometrial collagen synthesis and prostaglandin synthesis, which are not conducive to embryo implantation.

INSTRUMENT(S): Liquid Chromatography MS - negative - reverse phase, Liquid Chromatography MS - positive - reverse phase

PROVIDER: MTBLS10318 | MetaboLights | 2024-08-12

REPOSITORIES: MetaboLights