Abstract
Secretory epithelia and ductular glands were studied in main pancreatic ducts of guinea pig, rabbit, rat, and man. Brunner glands were studied for comparison. Semithin sections from Epon-embedded tissues were etched with sodium methylate and incubated with horseradish peroxidase-conjugated lectins. Columnar cells in the epithelium of pancreatic ducts are endowed with well-developed microvillar borders. These apical regions strongly stain with Lotus A-, wheat germ-, and Ricinus I-lectins. Basolateral plasma membranes bind Ricinus I-, Ulex europaeus I-, and wheat germ-lectins. Cytosomes in the supranuclear regions of epithelial cells are interpreted as secretory granules. These droplets are marked by wheat germ-lectin and to a lesser degree by Ricinus I- and Ulex europaeus I-lectins. Ductular glands of the main pancreatic ducts contain secretions that bind Helix-, wheat germ-, and Ulex europaeus I-lectins. Their apical and basolateral cell membranes deeply stain with wheat germ- and Ulex europaeus I-lectins. Secretions of Brunner glands bind Ricinus I-, Ulex europaeus I-, Helix-, and wheat germ lectins. Their apical and basolateral cell membranes stain with Ricinus I- and wheat germ-lectins.-Species differences in lectin-binding affinities of complex carbohydrates were observed and are described.