207 GLYCONJUGATES IN THE ESOPHAGEAL STRATIFIED SQUAMOUS EPITHELIUM

IntroductionThe stratified squamous epithelium plays an important role in protecting the tissue from acid reflux. It has three layers of cells: (1) the stratum germinativum, the cells of which divide and differentiate as they move upward toward the lumen to form the (2) stratum spinosum, and (3) the stratum corneum. Glycosylation is a very important determinant of biochemical and biologic properties of cell surface glycoproteins. Lectins can recognize specific carbohydrate residues on the cell membranes and have been used to study carbohydrate contents in several preparations.MethodsWe have studied the lectin binding profile on tissue sections of squamous epithelia from human biopsies and from pig esophagi. We have found that the binding to a specific lectin is heterogeneous in the three layers of the mucosa depending on the lectin used. We have used wheat germ agglutinin (WGA), Dolichos biflorus agglutinin (DBA), Vicia villosa agglutinin (VVA), peanut agglutinin (PNA), soybean agglutinin (SBA), and Ulex europaeus agglutinin (UEA).ResultsThe basal layer of cells did not show binding to the lectins. The stratum spinosum and corneum showed different intensities of staining to different lectins showing the presence of specific sugars in the different layers of the tissue.Conclusionα-l-fucose, N-acetylneuraminic acid, and N-acetylglucosamine residues are present in the stratum spinosum and corneum of the esophagus. Their presence could not be detected in the basal cells. The role of these sugar moieties in the structure and function of the mucosa remains to be determined.Support: VA Merit grant.