Histochemical analysis of glycoconjugates in the domestic cat ductuli efferentes

Ductuli efferentes have recently gained importance in view of 1) their role in the absorption of intraluminal fluid, 2) expression of estrogen receptors, 3) spermiophagy, and 4) potential secretion of glycoconjugates. The presence of glycoconjugates in the epithelium of the cat ductuli efferentes was investigated in this study. Tissues from adult cats were fixed in Bouin’s fluid and in 4% (w/v) neutral formalin and then embedded in paraffin wax. Sections were stained with 12 lectins in combination with sialidase treatment. Ciliated cells displayed oligosaccharides ending with D-GlcNAc throughout the cytoplasm and glycans with internal βGlcNAc in the supra-nuclear cytoplasm. The cilia glycocalix expressed glycans with terminal Galβ1,4GlcNAc, GalNAc, βGlcNAc, sialic acid-Galβ1,4GlcNAc and sialic acid-GalNAc. Non-ciliated cells showed oligosaccharides terminating with NeuAcα2,6Gal/GalNAc, sialic acid-Galβ1,3GalNAc, sialic acid-GalNAc and Galβ1,4GlcNAc on the luminal surface. The supra-nuclear cytoplasm displayed glycans terminating with sialic acid-Galβ1,3GalNAc in most non-ciliated cells, as well as Galβ1,4GlcNAc and sialic acid-Galβ1,4GlcNAc in a few scattered cells. The glycans expressed in both the supra-nuclear cytoplasm and the luminal surface of non-ciliated cells could be related to the synthesis and secretion of glycoconjugates that may bind to the spermatozoa during the flow from testis to the epididymis