In the gastrointestinal tract, Class III mucin-secreting 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 d
eveloped monoclonal antibody, HIK 1083, at the light microscopic level. In
the present study, we compared HIK 1083 staining with paradoxical Concenava
lin A type III staining (PCS) and GSA-II lectin staining, and found that al
l three methods revealed the same reactivity at both the light and electron
microscopic levels, HIK 1083 staining exhibited highly selective reactivit
y with cardiac mucous cells, mucous neck cells, pyloric gland cells and Bru
nner's gland cells. These results indicate that mucus-secreting cells of fo
regut origin share a common lineage and contain the same cell phenotype. Cl
ass III mucin secreted by these cells was characterized by the presence of
a peripheral alpha-GlcNAc residue on the carbohydrate moiety of its constit
uent glycoproteins. Because of the ease and specificity of immunostaining u
sing monoclonal antibody HIK 1083, it could replace PCS staining for both l
ight and electron microscopy.