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The secretion of the goblet cells in the intestine of Trachemys scripta elegans was studied in situ by histochemical methods to analyze the diversity of sugar chains, with particular regard to the acidic glycans. Conventional histochemical stains (Periodic acid-Schiff, Alcian Blue pH 2.5, High Iron Diamine) and binding with ten FITC-labelled lectins combined with chemical and enzymatic pre-treatments were used to characterize the oligosaccharidic chains. The intestine can be divided into three regions, i.e. a duodenum, a small intestine and a large intestine. Goblet cells were observed in all the three tracts and presented an acidic secretion. WGA, LFA, PNA and SBA binding was observed only after desulfation. Glycans secreted by the three tracts consist mainly of sulfosialomucins with 1,2-linked fucose, mannosylated, glucosaminylated and subterminal galactosyl/galactosaminylated residuals. Differences among tracts are quantitative rather than qualitative, with sulfated, galactosaminylated and glycosaminylated residuals increasing from duodenum to large intestine, and galactosylated and fucosylated residuals showing an opposite trend. Variation is observed also between apices and bases of villi in both duodenum and small intestine, where sulphation decreases from the base to the apex and glycosylation shows an opposite trend. Functional implication of these findings is discussed in a comparative context., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Characterization of mucins in the alimentary tract of the grass snake, Natrix natrix was performed by histochemical (PAS, Alcian Blue, pH 2.5 and pH 1.0, sialidase-Alcian Blue, pH 2.5, HID-AB pH 2.5) and lectin-histochemical (WGA, SWGA, PNA, sialidase-PNA, SBA, sialidase-SBA, DBA, sialidase-DBA, ConA, BSI-B4, AAA, UEA-1, LTA) techniques. Oesophageal lining epithelium consisted of ciliated and goblet cells, with no pluricellular glands. Mannosylated sialosulfomucins were observed. Fundic mucosa of stomach presented surface cells producing sialomucins with terminal sialic acid linked to galactose. In gastric glands neck and oxynticopeptic cells were found. Neck cells had sialomucins with mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine and fucose-α-(1,2)-linked residues. Cytoplasm of oxynticopeptic cells showed N-acetylgalactosamine and fucose residues. Secretion of surface cells in pyloric mucosa was similar to that of fundic ones, differing in having fucose. Goblet cells in the small intestine of N. natrix produced sulfo- and sialomucins, with sialic acid linked to galactose and N-acetylgalactosamine residues. Mucins also presented residues of mannose. Goblet cells in the large intestine presented sulfomucins only, with terminal N-acetylgalactosamine, galactose and N-acetylglucosamine. The glycosylation patterns found are probably related to protection against injuries, gastric juice and microorganisms, both pathogenic and decomposers, as well as to dietary adaptations., (Copyright © 2012 Elsevier Ltd. All rights reserved.)