Extracellular vesicles of boar seminal plasma contain oxytocin at levels associated with fertility, reveals research

Seminal EVs were isolated by size-exclusion chromatography from ejaculates of male pigs used in artificial insemination (AI) programs. The seminal EVs were characterized according to the International Society of Extracellular Vesicles guidelines (MISEV2023). OXT levels were measured using a direct competitive immunoassay based on AlphaLISA technology and an anti-OXT monoclonal antibody.

The results showed that male pig seminal EVs carry OXT, which is primarily located on the outer surface of the EV membrane, likely within the protein corona. Seminal EVs from the accessory sex glands were particularly enriched in OXT. The levels of oxytocin (OXT) in seminal EVs were related to the fertility of male pigs. Specifically, OXT levels were positively associated with the farrowing rate of inseminated sows, but negatively associated with the number of piglets born per litter. This ambivalence may reflect the proposed role of seminal OXT-containing EVs in stimulating myometrial contractility. This would improve sperm transport and fertilization, but hinder embryo implantation.

Reference

Parra A, Martínez-Díaz P, Botía M, López-Arjona M, Lucas X, Barranco I, Roca J. The extracellular vesicles of boar seminal plasma contain oxytocin at levels associated with fertility. Extracell Vesicles Circ Nucleic Acids. 2025;6:1000-14. https://dx.doi.org/10.20517/evcna.2025.94