Histochemical Characterization of Glycoconjugates Present in Cloacal Epithelium of the Chicken

Abstract

The distribution of glycoconjugates in the chicken cloaca was studied by means of light microscopic histochemical methods. The staining procedures employed were horseradish peroxidase conjugated lectin, Alcian blue (AB) pH 1.0, AB pH 2.5, periodic acid–Schiff (PAS), AB pH 2.5-PAS in combination with enzyme neuraminidase digestion. The lectin used in the present study were peanut agglutinin (PNA), wheat germ agglutinin (WGA), Dolichos biflorus agglutinin (DBA), and Lotus tetragonolobus agglutinin (LTA) The mucosa of both coprodeum and urodeum is covered by simple columnar epithelium in which 2 type of cells are encountered-columnar and goblet cells. In contrast, one layer of only columna cells is found in the mucosa of proctodeum. Tubular glands of proctodeum are commonly provided at submucosal layer. All the goblet cells in coprodeum and urodeum and tubular glands of proctodeum were coloured blue and purple with AB pH 1.0 and AB pH 2.5-PAS, respectively. They were furthermore stained moderately with WGA. Neuraminidase digestion changed the blue coloration with AB pH 2.5 to pale blue. Removal of sialic acid with neuraminidase imparted weak to strong affinity of PNA. Histophysiological significances of glycoconjugates involved in the chicken cloaca were discussed with special reference to the functional activities of the carbohydrates.