In Situ Identification of Sugar Residues in Monkeysʹ Salivary Glands by Lectin Histochemistry. II-Parotid Gland

The parotid salivary gland (PSG) of the monkey was histochemically analyzed by lectin histochemistry aiming to investigate the features of the available sugar residues and their suggested biology. These lectins were used as probe and the horseradish peroxidase (HRP) as visualant. The intensity of lectin binding affinity of the secretory acini and the smaller excretoiy ducts (intercalated, striated and interlobular ducts) showed wide variations. The reaction of the serous acini was strong with the Wheat germ agglutinin (WGA), moderate with the Ulexus europeus agglutinin-1 (UEA-1), scanty with the Concanavalia ensiformes agglutinin (Con-A) and negative with Peanut agglutinin (PNA). The lining epithelial cells of the intralobular ducts (intercalated and striated ducts) showed strong reaction to WGA, Con-A and PNA. While those of the interlobular ducts were negative to all lectins used except the moderate reaction to PNA. The goblet cells of the interlobular duct gave strong reaction with WGA only. In conclusion, the present study suggested that, the nature and composition of stored glycoproteins in monkey PSG is heterogeneous. The predominant terminal sugar residues are supposed to be N-acetylglucosamine (a-D-GlcNAc) in secretoiy acini and a D-glucose (a-D-glc) and a D-mannose (a-D-man) in the ducts system.