Authors: Piotrowska-Tomala Katarzyna K, Jonczyk Agnieszka W, Szóstek-Mioduchowska Anna Z, Żebrowska Ewelina, Ferreira-Dias Graca, Skarzynski Dariusz J
Journal: Frontiers in veterinary science
Summary
# Editorial Summary Prostaglandin E2 (PGE2) has long been recognised as a luteotrophic agent in equine reproduction, yet questions remained about whether its route of administration—directly into the corpus luteum versus into the uterine lumen—might produce meaningfully different outcomes on luteal function. Piotrowska-Tomala and colleagues investigated this by comparing intra-corpus luteum (CL) and intrauterine (intra-U) administration of PGE2 (5 mg) alongside hCG as a positive control in six mares per treatment group, measuring plasma progesterone and PGE2 concentrations across a 24-hour period. Both routes successfully stimulated progesterone secretion, though with distinct temporal profiles: direct CL injection elevated progesterone between 3–4 hours post-treatment, whilst intrauterine administration delayed the response until 8–24 hours, suggesting systemic absorption and indirect signalling mechanisms may be involved in the latter route. The findings confirm that PGE2 supports luteal function regardless of application site, which has practical implications for practitioners employing prostaglandin supplementation in mares with inadequate luteal phase progesterone; however, the timing differences indicate that injection site selection could influence the speed of therapeutic effect and should be considered when managing specific reproductive scenarios.
Read the full abstract on PubMed
Practical Takeaways
- •PGE2 administration can enhance corpus luteum function and progesterone secretion in mares, with application route determining response timing—intra-corpus luteum injection produces faster effects (3-4h) versus intrauterine administration (8-24h)
- •These findings may inform therapeutic protocols for mares with inadequate progesterone production or luteal insufficiency, though clinical application protocols require further development
- •Route of PGE2 administration should be carefully selected based on desired onset of progesterone elevation in reproductive management scenarios
Key Findings
- •Intra-corpus luteum PGE2 injection increased progesterone and PGE2 concentrations at 3-4 hours post-treatment (p<0.05)
- •Intrauterine PGE2 administration elevated progesterone concentrations between 8-24 hours post-treatment (p<0.05)
- •Both intra-corpus luteum and intrauterine PGE2 application supported corpus luteum function in a dose-dependent manner
- •Application site (intra-corpus luteum vs intrauterine) significantly affected the timing and magnitude of progesterone and PGE2 response