Immunohistochemical and lectin histochemical analysis of the alpaca efferent ducts
F. Parillo1, G.E. Magi1, S. Diverio2 and G. Catone1
1Department of Veterinary Science, Faculty of Veterinary Medicine, University of Camerino, Matelica, Italy and 2Department of Biopathological Science and Hygiene of Animal and Food Productions, Faculty of Veterinary Medicine, Universiy of Perugia, Perugia, Italy.
Offprint requests to: Prof. Francesco Parillo, Dipartimento di Scienze Veterianarie, Facoltà de Medicina Veterinaria, Università degli Studi di Camerino-UNICAM, via circonvallazione 93-95, Matelica, Italy. e-mail: francesco.parillo@unicam.it
Summary. An immunohistochemical and lectin histochemical study of the efferent ducts was performed in the alpaca. Two types of epithelium, consisting of principal and ciliated cells, were detected on the basis of the different cytokeratins expression and lectin binding pattern. AE1/AE3 and 13 cytokeratin antibodies intensely immunostained the entire cytoplasm of type I PCs, whereas AE1/AE3, but not anti cytokeratin 13, immunoreacted in type II principal cells along the apical, lateral and basal plasma-membrane.
The histochemical characterization of the epithelial cells was carried out using a battery of different lectins: Con-A, UEA-I, LTA, WGA, GSA-II, GSA-IB4, SBA, PNA, ECA, DBA, MAL-II and SNA. Sialidase digestion and deglycosilation pre-treatments were also employed.
In type I principal cells, the staining of the Golgi zone was interpreted giving evidence for the synthesis and secretion of O- and N-linked oligosaccharides. In particular, α-Man/α-Glc, GlcNAc, ß-Gal-(1-4)-GlcNAc, Neu5Acα2,3Gal and Neu5Acα2,6Gal/GalNAc residues were included in both O- and N-linked glycans, whereas α-Fuc, ß-GalNAc and α-Gal were only found in O-linked oligosaccharides; α-GalNac and ß-Gal-(1-3)-D-GalNAc were found subterminal to sialic acid moieties and they were included in O- and N-glycans. In type II principal cells, the lectin staining was observed in the apical cytoplasmic granules and in vacuoles that were interpreted as components of an elaborate endocytotic apparatus specialized for the uptake of particulate material and fluid from the lumen. These results suggest the existence of two structurally different epithelial segments along the ductuli efferentes of the alpaca, with a high degree of compartmentalization of the secretory and absorptive activities. Histol Histopathol 24, 1-12 (2009)
Key words: Cytokeratins, Lectins, Efferent ductules, Alpaca
DOI: 10.14670/HH-24.1