Microvascularization and Expression of Fibroblast Growth Factor and Vascular Endothelial Growth Factor and Their Receptors in the Mare Oviduct.
Authors: Pinto-Bravo Pedro, Rebordão Maria Rosa, Amaral Ana, Fernandes Carina, Galvão António, Silva Elisabete, Pessa-Santos Pedro, Alexandre-Pires Graça, Roberto da Costa Rosário P, Skarzynski Dariusz J, Ferreira-Dias Graça
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Vascularisation and Growth Factor Expression in the Mare Oviduct The oviduct's microenvironment critically influences fertilisation success and early embryonic development, yet regional variation in its vascular supply and angiogenic signalling remains poorly characterised in mares. Pinto-Bravo and colleagues examined microvascular density, vascular architecture, and gene/protein expression of key angiogenic factors (fibroblast growth factor 1 and 2, vascular endothelial growth factor) and their receptors across the three oviductal segments in cycling mares using vascular corrosion casting, immunohistochemistry, quantitative PCR, and Western blotting. The isthmus demonstrated the most substantial vascular area and highest microvessel count during the follicular phase, with notably upregulated expression of FGF1, FGFR1, FGF2, and VEGFR2 (KDR) in this region, reflected in elevated receptor protein abundance. These findings suggest that the distinct morphological and molecular profiles across the infundibulum, ampulla, and isthmus may underpin their specialised roles in gamete transport and early embryo support. For practitioners, understanding region-specific angiogenic activity could inform assessment of oviductal pathology, guide targeted therapeutic approaches to subfertility, and potentially inform protocols supporting embryonic development in assisted reproductive contexts.
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Practical Takeaways
- •Understanding regional vascularization differences in the oviduct may inform management of reproductive conditions and breeding outcomes in mares
- •Angiogenic factor expression varies by oviduct region and estrous cycle phase, which could influence embryo transport and early development environments
- •The isthmus shows enhanced vascular dynamics that may relate to its physiological role in gamete transport and early embryo development
Key Findings
- •The isthmus presented the largest vascular area and highest number of vascular structures in the follicular phase compared to infundibulum and ampulla
- •Angiogenic factors FGF1, FGF2, and VEGF and their receptors (FGFR1, FGFR2, KDR) were expressed throughout all oviduct regions across the estrous cycle
- •Upregulation of FGF1 and FGFR1 transcripts occurred in ampulla and isthmus, with FGF2 and KDR specifically upregulated in the isthmus
- •Relative protein abundance of FGFR1 and KDR was highest in the isthmus, correlating with regional microvascular density patterns