Browsing by Subject "Lectin histochemistry"

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    Absorptive activities of the efferent ducts evaluated by the immunolocalization of aquaporin water channels and lectin histochemistry in adult cats
    (Murcia: F. Hernández, 2010) Arrighi, S.; Ventriglia, G.; Aralla, M.; Zizza, S.; Di Summa, A.; Desantis, S.
    Ultrastructural and biochemical features of efferent ducts (EDs) are indicative of an intense absorptive activity towards the luminal fluid. This function was investigated by 1) the immunohistochemical localization of different aquaporins, integral membrane water channels that facilitate rapid passive movement of water, and 2) the histochemical localization of lectins, known to have specific affinity for glycoconjugate residues. AQP1 was mostly revealed at the apical surface and adluminal cytoplasm of non-ciliated cells and to a minor extent in their lateral plasma membrane, whereas it was absent in ciliated cells. Blood vessels showed AQP1-immunoreactivity, which was present in endothelial cells of venous vessels and capillaries and around the muscular sheath of arteries. AQP9 was expressed in the apical zone of ciliated and non-ciliated cells and in the lateral cell membrane. AQP2 and AQP5 were undetectable. Lectin histochemistry showed that non-ciliated cells contain glycans with terminal Neu5Acα2,3Galß1,3GalNAc, Neu5Acα2,3Galß1,4GlcNAc, Galß1,4GlcNAc, GalNAc (s-PNA, MAL II, RCA120, SBA reactivity) and with internal/terminal αMan (Con A affinity) at the luminal surface and the apical region. In addition, non-ciliated cells expressed oligosaccharides terminating with GalNAc and Neu5Acα2,6Gal/GalNAc (SNA reactivity) in the luminal surface and the apical zone, respectively. Ciliated cells revealed glycoconjugates only on cilia, which showed terminal Neu5Acα2,3Galß1,4GlcNAc (s-RCA120 staining) and GalNAc, as well as internal/terminal αMan and GlcNAc (s-WGA, GSA II staining). Data provide evidence for the involvement of different pathways in the bulk reabsorption of water and low molecular weight solutes by the non-ciliated cell of the cat EDs. AQP-mediated trans-cellular route can be hypothesized, together with fluid phase endocytosis mediated by the glycocalix and a well-developed endocytotic apparatus. Epithelial ciliated cells, whose main function is the movement of luminal content, might also participate in absorptive processes to a lesser extent
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    Histochemical study of glycoconjugates in the toadfish Halobatrachus didactylus oesophagus epithelium
    (Murcia : F. Hernández, 2007) Desantis, S.; Cirillo, F.; Deflorio, M.; Megalofonou, P.; Palazón, J.L.; Sarasquete, C.; De Metrio, G.
    The carbohydrate expression in the epithelium lining the oesophagus of the toadfish Halobatrachus didactylus was studied by means of conventional and lectin histochemistry. The stratified epithelium was constituted by basal cells, polymorphous cells in the intermediate layer, pyramidal and flattened cells in the outer layer and contained two types of large secretory cells: goblet cells and sacciform cells. PAS, Alcian blue pH 2.5 and pH 1.0 stained very strongly the goblet cells, weakly the surface of the other epithelial cells but did not stain the sacciform cells. The goblet cells cytoplasm contained oligosaccharides with terminal Galß1,3GalNAc, a/ßGalNAc, Galß1,4GlcNAc, aL-Fuc and internal ßGlcNAc residues (PNA, SBA, RCA120, UEA I, LTA and KOH-sialidase-WGA affinity). Galß1,4GlcNAc, aL-Fuc and internal ßGlcNAc were also found in the glycocalyx. The sacciform cells expressed sialyloligosaccharides terminating with Neu5Aca2,3Galß1,4GlcNac, Neu5Acß2,6Gal/GalNAc, Neu5AcForssman pentasaccharide (MAL II, SNA, KOH-sialidase-DBA staining) as well as asialoglycoconjugates with terminal/internal aMan (Con A affinity) and with terminal Galß1,3GalNAc, Forssman pentasaccharide, Galß1,4GlcNAc, GalNAc (HPA and SBA reactivity), aGal (GSA I-B4 reactivity), D-GlcNAc (GSA II labelling), aL-Fuc. The basal cells cytoplasm exhibited terminal/internal aMan and terminal Neu5Aca2,6Gal/GalNAc, Galß1,4GlcNAc, a/ßGalNAc, aGal, GlcNAc, aL-Fuc. Intermediate cells showed oligosaccharides with terminal/internal aMan and/or terminating with Neu5Aca2,6Gal/GalNAc, Galß1,4GlcNAc in the cytoplasm and with Neu5Aca2,3Galß1,4GlcNac, a/ßGalNAc, aGal, GlcNAc, aL-Fuc in the glycocalyx. The pyramidal cells expressed terminal/internal aMan and terminal Neu5Aca2,6Gal/GalNAc, a/ßGalß1,4NAc, aGal, aLFuc in the entire cytoplasm, terminal Neu5Aca2,3 Galß1,4GlcNac and Forssman pentasaccharide in the apical extension, internal ßGlcNAc and/or terminal aLFuc in the luminal surface, Neu5aca2,3Galß1,4GlcNac, Neu5Aca2,6Gal/GalNAc, Galß1,4GlcNAc, aGal in the basolateral surface. The flattened cells displayed glycans with terminal/internal aMan and terminal Neu5Aca2,6Gal/GalNAc, a/ßGalNAc, aGal, DGlcNAc in the entire cytoplasm, glycans terminating with Galß1,3GalNAc and/or internal ßGlcNAc in the sub-nuclear cytoplasm.
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    Lectin histochemistry of feline sphingomyelinosis
    (Murcia : F. Hernández, 1991) Kamiya, S.; Yamagami, T.; Umeda, M.; Sugiyama, M.; Daigo, M.
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    Lectin histochemistry of salivary glands in the Gian t An t-eater (Myrmecophaga tridactyla)
    (Murcia : F. Hernández, 1993) Meyer, W.; Beyer, C.; Wissdorf, H.
    The submandibular and buccal glands of the Giant Ant-eater (Myrmecophaga tridactyla) have been studied by means of a series of carbohydrate histochemical methods, including a broad spectrum of PO-lectin procedures. The seromucous cells (Gl. submandibularis) and mucous cells (Gl. buccalis) of the glandular acini, as well as the secretion in the excretory duct system exhibited very strong to strong reactions for neutral and acidic glycocongugates. The serous cells of the buccal glands and the excretory duct cells reacted rather weakly. The different controls applied particularly emphasized that sialoglycoconjugates are the predominant ingredients of the saliva secreted. Lectin histochemical differentiation demonstrated a varying pattern of saccharide residues in these substances. In the submandibular glands the glycocongujates (mostly proteoglycans) of the seromucous cells and the luminal secretion normally contained terminal B-galactose and minor contents of terminal a-N-acetylglucosamine. After sialidase digestion this cell type exhibited distinct amounts of sialic acid-B-galactose and sialic acid-a-N-acetylgalactosamine. Sialic acid was also clearly present in the tough interlobular connective tissue. The buccal glands showed a similar distribution of saccharide residues in the mucous cells. In the serous cells, however, acidic glycoproteins with sialyl residues were observed, also containing terminal a-D-mannosyl, a-N-acetylgalactosaminyl, and B-D-galactosyl residues. The cells of the excretory duct system of both gland types reacted weakly to moderately for terminal sugar residues (Nacetyl- D-glucosamine, N-acetyl-D-galactosamine, B-Dgalactose). The results obtained are discussed in view of the specific feeding mode of the Giant Ant-eater, whereby high contents of sialoglycoconjugates (proteoglycans, glycoproteins) produced by the salivary glands warrant for the main function of the non-sticky saliva; i.e., to act as an effective lubricant during tongue movement.