Phenotypic Immunostaining of Mucus-Secreting Cells of Foregut Origin

In the gastrointestinal tract, Class III mucinsecreting cells include the cardiac mucous cells, mucous neck cells, pyloric gland cells and Brunner's gland cells. It has been found that these cells are stained by a recently developed monoclonal antibody, HIK 1083, at the light microscopic level. In the present study, we compared HIK 1083 staining with paradoxical Concanavalin A type III staining (PCS) and GSA-II lectin staining, and found that all three methods revealed the same reactivity at both the light and electron microscopic levels. HIK 1083 staining exhibited highly selective reactivity with cardiac mucous cells, mucous neck cells, pyloric gland cells and Brunner's gland cells. These results indicate that mucus-secreting cells of foregut origin share a common lineage and contain the same cell phenotype. Class III mucin secreted by these cells was characterized by the presence of a peripheral α-GlcNAc residue on the carbohydrate moiety of its constituent glycoproteins. Because of the ease and specificity of immunostaining using monoclonal antibody HIK 1083, it could replace PCS staining for both light and electron microscopy.