Characterization of secretory cell glycoconjugates in the alimentary tract of the ruin lizard (Podarcis sicula campestris De Betta) by means of lectin histochemistry.

Abstract

Secretory cell glycoconjugates of the alimentary canal of the ruin lizard (Podarcis sicula campestris De Betta) were characterized by traditional staining methods and by lectin histochemistry. The goblet cells of the upper esophagus produced sialo- and sulfomucins, while those of the lower esophagus mainly contained sulfomucins. Lectin histochemistry demonstrated the presence of N-acetyl-D-glucosamine and terminal sialic acid. The epithelial mucous cells lining the surface of the stomach and the gastric pits contained neutral glycoproteins with glycosidic residues of N-acetyl-D-galactosamine, D-glucose, D-mannose, D-galactose, and N-acetyl-D-glucosamine. The mucous cells of the gastric glands produced neutral glycoproteins that contained stable class-III mucosubstances, as revealed by Paradoxical Con A staining, with terminal residues of L-fucose and D-galactose. They can be similar to the true neck cells of the gastric pits of other vertebrates. The goblet cells of the small intestine produced acidic glycoproteins with glycosidic residues of N-acetyl-D-glucosamine, sulfated esters on internal residues and terminal sialic acid. In the large intestine, there is a predominance of sulfated mucosubstances with D-galactose, N-acetyl-D-glucosamine, and N-acetyl-D-galactosamine. The microheterogeneity of mucins of the digestive tract, as proved by lectin histochemistry, is probably connected to their different functions.