Changes in lectin binding patterns in rat esophageal epithelium during development

Changes in lectin binding patterns during the development of rat esophageal epithelium were examined by light- and electron-microscopy. For the light microscopical observations, 15 kinds of biotinylated lectins were used. Stainings with these lectins were weak before 17 days p.c. (post coitum). On the other hand, positive reactions were progressively observed after 18 days p.c. Among them, ConA and WGA showed a positive reaction on all layers of the epithelium; whereas DSA was positive for the middle and surface layers and UEA-1 was positive for only the middle layer. Electron microscopical observations revealed that UEA-1 showed a strongly positive reaction along the cell membranes of middle-layer cells, and on the apical cell membranes of basal cells. It also showed positive staining on Golgi membranes of the cells in the middle layer. ConA and DSA showed a positive reaction on cell, Golgi, and nuclear membranes. It was confirmed that the differentiation of the three layers (surface, middle and basal layers) of epithelial cells morphologically started to be observed after 17 days p.c. These results suggest that the distribution of glycoproteins in the esophageal epithelium changes in accordance with mucous epithelial cell differentiation.