Histochemical Analysis of Sialoglycoconjugates in the Luminal Surface of the Ampulla of Horse Oviduct

Sialic acids usually occupy thè tenninal position of the oligosaccharide chains of glycoconjugates thus providing a negative charge likely to be important in the cell-to-cell interactions occurring in the oviduct. In this study we in vesti gated the sialyloligosaccharide expression on the luminal surface of the ampolla epithelium of marea by means of lectin histochemistry. Ampullae from filly (n = 1), oestrus (n = 2), pregnant (n = 2) and anoestrus (n = 2) mares were fixed in 4% (w/v) neutral formalin and routinely embedded in paraffin wax. In hydrated sections, the NeuSAca2,3Gal/Bl,4GlcNAc and Neu5Aca2,6Gal/GalNAc sequences were detected with MAA (Maackia amurensis) and SNA (Sambucus nìgra). The NeuSAcGalB1,3GalNAc, Neu5Ac-Forssman pentasaccharide, Neu5aca/BGalNAc, and Neu5AcGalB1,4GlcNAc sequences were marked with PNA (Arachis hypogea), DBA (Dolichos biflorus), SBA (Glycine max), RCAl2o (Ricinus communis), after KOHsialidase (K-s) treatments. The luminal surface of the ciliated (CC) and the secretory (SC) cells of thè ampulla epithelium from ah1 specimens stained with the K-s-SBA procedure. The CC luminal surface showed reactivity to MAA, SNA, K-s-PNA, and K-s-DBA. K-s-DBA did not stain in pregnancy. The SC apical surface bound MAA and K-s-PNA in oestrus and pregnancy, K-s-DBA in oestrus and anoestrus, and SNA in oestrus only. The demonstrated cellular and time-dependent differences in the luminal surface sialyloligosaccharides of the mare a